Hdpe Procedure 2a4x4j
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METHOD STATEMENT for HPDE
DYNAMIC INDUSTRIAL ENGINEEING LLC PROJECT
High-density polyethylene (HDPE) PIPE WORK
PROCEDURE FOR WELDING AND INSTALLATION -
5180.DE.P10.950.R0
Revision History 0
27/03/13
WasiUllah Zeeshan
HDPE PIPE WORK
QA-QC Mngr
Rev No
Date
Description
Prepared By
Bahadur Khan Managing Director
Approved By
Notice All rights reserved. These materials are confidential and proprietary of Dynamic Engineering. No part of these materials should be reproduced, published in any form by any means (electronic or mechanical, including photocopy or any information storage or retrieval system), nor should the materials be disclosed to third parties without express written authorization of Dynamic Engineering.
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METHOD STATEMENT for HPDE
TABLE OF CONTENTS
1. Scope & General Provisions 1.1 Scope 1.2 General (Overview) 1.3 Responsibilities 2. References 3. & Definitions 4. Safety First 4.1
Safety Alerts
4.2
Read and understand
4.3
General Safety
4.4
Wear Safety Equipment
4.5
Units with hydraulics
4.6
Heaters are not explosion proof
4.7
Electric motors are not explosion proof
4.8
Electric Safety
4.9
Crush Point
4.10
Facer Blades are sharp
4.11
Heater is hot
4.12
Fusion Procedure
4.13
Units with Gas Engine
4.14
Units with battery
4.15
Have tiers properly serviced
4.16
Periodically check Temperature
4.17
Fusion Tow Speed
4.18
Fusion Machine Positioning
4.19
Edge of Ditch
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METHOD STATEMENT for HPDE
4.20
Track-star Fusion machine
4.21
Track-Star machine towing
4.22
PPE
4.23
Guarding against static electricity and gaseous Ignitions
5. Quality Control 6. Storage & handling 6.1 Storage 6.2 Handling 7. Installation Instructions 7.1 Work Flow Chart 7.2 Accessories and Special tools 7.3 Before Start 8. Applications 8.1 Welding Conditions 8.2 Pipe Alignment 8.3 Preparation of Pipe Ends 8.4 Welding Parameters 8.5 Heating of Surface 8.6 Fusion of Surface 8.7 Holding 8.8 Cooling of Surface 9. Inspection 9.1 Welding Checks 9.2 Defects and Causes 9.3 Rules for Butt Weld Fusion 9.4 Report 10. Pressure Testing 10.1
Pressure Testing Outside the Trench
10.2
Pressure Testing Inside the Trench
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METHOD STATEMENT for HPDE
1- SCOPE & GENERAL PROVISION 1.1-
Scope The scope of this model specification is for municipal water pipelines which conform to AWWA standards. This model specification provides minimum requirements for HDPE pipe and fittings to be used in the design and construction of municipal pressure piping projects. This document describes the Safety, Quality, Inspection, Preparation and Welding Procedure of the polyethylene pipe & fittings by fusion weld, it is to insure that the welded t will perform equal to or greater than pipe. This section specifies high density polyethylene pipe (HDPE) and fittings for water utility use as indicated on the Drawings, and as specified herein. • Furnish, Install, and Test HDPE pipe as indicated and specified in this section, and as referred to in related sections, and the Drawings for the Project. • The primary installation method is burial. The means and methods, including the testing for acceptance shall conform to all applicable standards as noted herein with the intention of providing a leak-free system to the owner.
1.2-
General (Overview) In butt fusion ing, mating surfaces are prepared, mating faces are melted with a hot plate heater, the heater is removed, and the melted surface are pressed together and held under pressure. As the molten material cool, they mix and fuse into a permanent, (homogeneous) monolithic t. DYNAMIC INDUSTRIAL ENGINEERING LLC pipe fusion procedure require special tools & equipment for the size of pipe and fittings being ed.
1.3-
Responsibilities The following duties are not limited and will be added to those mentioned in QA Manual. Management – Shall review/approve all the procedures and are prepared as per engineering design requirements. Quality and safety is implemented, maintained and monitored systematically. Engineer – shall prepare all the procedures before commencing of work. Must Ensure/monitor/supervise all work is being carried out as per engineering design requirements. Must carry out tool box talk, Checks, Inspects and Reports to Project
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METHOD STATEMENT for HPDE
Manager or higher management. Must raise NCR if the work is fall out of the acceptable criteria. Keep follow-ups with the corrective actions. Welder – Shall Prepare the Weld t and keep welding parameters as specified in the welding procedure. Must follow safety measure and precautions strictly.
2- REFERENCES To the extent referenced in this specification section, the standards and documents listed below are included, and made a part of this specification. In the event of a conflict, the requirements of this specification section prevail. Unless otherwise specified, references to documents shall mean the latest published edition of the referenced document in effect at the bid date of the project. ANSI/AWWA • ANSI/AWWA C901-08 Polyethylene (PE) Pressure Pipe and Tubing, ½ In. (13 mm) Through 3 In. (76 mm) for Water Service • ANSI/AWWA C906-07 Polyethylene (PE) Pressure Pipe and Fittings, 4 In. (100 mm) Through 63 In. (1,600 mm), for Water Distribution and Transmission • ANSI/AWWA C651 Standard for Disinfecting Water Mains • AWWA M55 Manual of Water Supply Practices, PE Pipe–Design and Installation Plastics Pipe Institute, PPI • PPI Handbook of Polyethylene Pipe – 2009 (2nd • PPI TR-33 Generic Butt Fusion ing Procedure for Polyethylene Gas Pipe Edition) • PPI TR-34 Disinfection of Newly Constructed Polyethylene Water Mains • PPI TR-41 Generic Saddle Fusion ing Procedure for Polyethylene Gas Piping • PPI TN-42 Recommended Minimum Training Guidelines for PE Pipe Butt Fusion ing Operators for Municipal and Industrial Projects (2009) NSF • NSF / ANSI 61 Drinking Water System Components–Health Effects ASTM • ASTM F 714 Standard Specification for Polyethylene (PE) Plastic Pipe (SDRPR) Based on Outside Diameter • ASTM F905 Standard Practice for Qualification of Polyethylene Saddle-Fused ts • ASTM F 1055 Standard Specification for Electro fusion Type Polyethylene Fittings for Outside Diameter Controlled Polyethylene Pipe and Tubing • ASTM F 1290 Standard Practice for Electro fusion ing Polyolefin Pipe and Fittings • ASTM F 1412 Standard Specification for Polyolefin Pipe and Fittings for Corrosive Waste Drainage Systems
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METHOD STATEMENT for HPDE
• ASTM F1417 Standard Test Method for Installation Acceptance of Plastic Gravity Sewer Lines Using Low-Pressure Air • ASTM F 2164 Standard Practice for Field Leak Testing of Polyethylene (PE) Pressure Piping Systems Using Hydrostatic Pressure • ASTM F2206 Standard Specification for Fabricated Fittings of Butt-Fused Polyethylene (PE) Plastic Pipe, Fittings, Sheet Stock, Plate Stock, or Block Stock • ASTM D 2239 Standard Specification for Polyethylene (PE) Plastic Pipe (SIDRP) Based on Controlled Inside Diameter • ASTM D 2321 Standard Practice for Underground Installation of Thermoplastic Pipe for Sewers and Other Gravity-Flow Applications • ASTM F 2620 Standard Practice for Heat Fusion ing of Polyethylene Pipe and Fittings • ASTM D 2683 Standard Specification for Socket-Type Polyethylene Fittings for Outside Diameter-Controlled Polyethylene Pipe and Tubing • ASTM D 2737 Standard Specification for Polyethylene (PE) Plastic Tubing • ASTM D 2774 Standard Practice for Underground Installation of Thermoplastic Pressure Piping • ASTM D 3261 Standard Specification for Butt Heat Fusion Polyethylene (PE) Plastic Fittings for Polyethylene (PE) Plastic Pipe and Tubing • ASTM D 3350-08 Standard Specification for Polyethylene Plastics Pipe and Fittings Materials.
3- & DEFINATIONS
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METHOD STATEMENT for HPDE
OPI PPI AWWA ASTM FMS NSF HDPE PE PVC DI DIPS IPS CTS ID OD PSI PSI DR SDR PS WP 4- WPR MJ DIMJA NPT Tubing Perf FOB
Oxford Plastic Inc Plastic Pipe Institute American Water Works Association American Society of Testing and Materials Factory Mutual Standards National Sanitation Foundation High Density Polyethylene Polyethylene Poly Vinyl Chloride Ductile Iron Ductile Iron Pipe Size Iron Pipe Size Copper Tube Size Inside Diameter Outside Diameter Pounds Per Square Inch Pounds Per Square Inch Dimension Ratio Standard Dimension Ratio Pressure Surge Working Pressure Working Pressure Rating Mechanical t Ductile Iron Mechanical t Assembly National Pipe Thread HDPE Corrugated Tubing HDPE Perforated Corrugated Tubing Freight on Board
SAFETY FIRST 4.1-
Safet y
Alerts This hazard alert sign
Appears in this manual. When you see this sign,
carefully read what it says. YOUR SAFETY IS AT STAKE. You will see the hazard alert sign with these words: DANGER, WARNING, and CAUTION.
Indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
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METHOD STATEMENT for HPDE
Indicates a hazardous situation which, if not avoided, may result in minor or moderate injury. In this manual you should look for two other words: NOTICE and IMPORTANT. NOTICE: Can keep you from doing something that might damage the machine or someone’s property. It may also be used to alert against unsafe practices. IMPORTANT: Can help you do a better job or make your job easier in some way.
4.2-
Read and Understand Do not operate fusion equipment until you have carefully read, and understand the “Safety” and “Operation” sections of this manual, and all other equipment manuals that will be used with it. Your safety and the safety of others depends upon care and judgment in the operation of this equipment. Follow all applicable federal, state, local, and industry specific regulations
4.3-
General Safety DYNAMIC INDUSTRIAL ENGINEERIN LLC cannot anticipate every possible circumstance that may involve a potential hazard. The warnings in this manual and on the machine are therefore not all inclusive. You must satisfy yourself that a procedure, tool, work method, or operating technique is safe for you and others. You should also ensure that the machine will not be damaged or made unsafe by the method of operation or maintenance you choose. Safety is important. Report anything unusual that you notice during set up or operation. Listen For thumps, bumps, rattles, squeals, air leaks, or unusual sounds. Smell Odors like burning insulation, hot metal, burning rubber, hot oil, or natural gas. Sense Any changes in the way the equipment operates. See Problems with wiring and cables, hydraulic connections, or other equipment. Report
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METHOD STATEMENT for HPDE
Anything you see, feel, smell, or hear that is different from what you expect, or that you think may be unsafe
4.4-
Wear Safety Equipment Wear a hard hat, safety shoes, safety glasses, and other applicable personal protection equipment. Remove jewelry and rings, and do not wear loose-fitting clothing or long hair that could catch on controls or moving machinery.
4.5-
Units with Hydraulics Although the hydraulic pressures in the machine are low compared to some hydraulically operated equipment, it is important to that a sudden hydraulic leak can cause serious injury or even be fatal if the pressure is high enough. Escaping fluid under pressure can penetrate the skin causing serious injury. Keep hand sand body away from pinholes which eject fluid under pressure. Use a piece of cardboard or paper to search for leaks. If any fluid is injected into the skin, it must be immediately removed by a doctor familiar with this type of injury. NOTICE: Wear safety glasses, and keep face clear of area when bleeding air from hydraulic system to avoid spraying into eyes
4.6-
Heaters are Not Explosion Proof
Operation of a heater in a hazardous environment without necessary safety precautions will result in explosion and death. When operating in a hazardous environment, heater should be brought up to temperature in a safe environment, then unplugged before entering the hazardous atmosphere for fusion.
4.7-
Electric Motors are Not Explosion Proof
Electric Motors are not explosion proof. Operation of these components in a hazardous environment without necessary safety precautions will result in explosion or death. When operating in a hazardous environment, keep pump motor and chassis in a safe area by using hydraulic extension hoses
4.8-
Electric Safety
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METHOD STATEMENT for HPDE
Always ensure power cords are properly grounded. It is important to that when you are working in a wet environment with electrical devices, proper ground connections help to minimize the chances of an electric shock. Frequently inspect electrical cords and unit for damage. Damaged components need to replaced and service performed by a qualified electrician. Do not carry electrical devices by the cord.
NOTICE: Always connect units to the proper power source as listed on the unit, or in the owner’s manual. On units with two power cords, plug each cord into separate power circuits. Do not plug into both outlets of one duplex receptacle. NOTICE: Disconnect the machine from the power source before attempting any maintenance or adjustment
4.9-
Crush Points
Hydraulically operated jaws are operated under pressure. Anything caught in the jaws will be crushed. Keep fingers, feet, arms, legs, and head out of the jaw area. Always check pipe alignment with a pencil or similar object.
4.10- Facer Blades Are Sharp
Facer blades are sharp and can cut. Never attempt to remove shavings while the facer is running, or is in the facing position between the jaws. Use care when operating the facer, and handling the unit. NOTICE: Disconnect power from the facer, and remove the facer blades before attempting any maintenance or adjustment.
4.11-
Heater is Hot
The heater is hot and will burn clothing and skin. Keep the heater in its insulated heater stand or sling blanket when not in use, and use care when heating the pipe. NOTICE:
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METHOD STATEMENT for HPDE
Use only a clean non-synthetic cloth such as a cotton cloth to clean the heater plates
4.12- Fusion Procedure
Follow the procedures carefully, and adhere to all specified parameters. Failure to follow procedures could result in a bad weld. Always follow the proper fusion procedures.
4.13- Units With Gas Engines
Handle fuel with care. Fuel is highly flammable. Do not refuel the machine while smoking or near open flames or sparks. Always stop the engine before refueling machine. Fill fuel tank outdoors. Help prevent fires by keeping machine clean of accumulated trash, grease, debris, and facer shavings. Always clean up spilled fuel.
Breathing exhaust gases can cause sickness or death. Always operate machine outdoors in an area with adequate ventilation
4.14- Units with Batteries
Sulfuric acid in battery electrolyte is poisonous. It is strong enough to burn skin, eat holes in clothing, and cause blindness if splashed into eyes. Avoid with eyes, skin, and clothing. Exploding gases from battery could cause blindness or serious injury. Keep sparks, flames and cigarettes away.
4.15- Have Tiers Properly Serviced
Failure to follow proper procedures when mounting a tire on a wheel or rim can produce an explosion which may result in serious injury or death. Have tires mounted by someone that is experienced, and has the equipment to perform the job safely
4.16- Periodically Check Temperature NOTICE:
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METHOD STATEMENT for HPDE
Incorrect heating temperature can result in bad fusion ts. Check heater plate surface temperature periodically with a pyrometer, and make necessary adjustments. The thermometer on heaters indicates internal temperature, and should be used as a reference only
4.17- DO NOT Tow Fusion Machine
The chassis is not designed for over-road towing. Towing at speeds greater than (05) five miles per hour can result in machine damage as well as injury. Always transport the machine by flatbed truck or similar means, and make sure that unit is properly secured.
4.18- Position Fusion Machine Place fusion machine on as level ground as possible, and set the brake on the rear wheel. If it is necessary to operate machine on un-level grade, chock the wheels and block the unit to make it as stable as possible
4.19- Keep Machine Away from Edge of Ditch
Heavy equipment too close to a ditch can cause the walls of the ditch to cave-in. Keep the machine far enough away from the edge of the ditch to prevent injury to personnel and equipment from a cave-in
4.20- Operating Trac-Star Fusion Machines Place fusion machine on as level ground as possible. If it is necessary to operate machine on un-level grade, make sure that the ground is stable. Some unstable conditions maybe ice, snow, mud, and loose gravel.
For operation safety, never operate machine on a grade steeper than 30%. (A 3 foot elevation change in 10 feet.)
4.21- Do Not Attempt to Tow A Trac-Star Fusion Machine
The machine is not designed for towing. Attempting to tow the machine can result in machine damage. Always transport the machine by flatbed truck or similar means, and make sure that unit is properly secured.
4.22- Protective Equipment
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METHOD STATEMENT for HPDE
When operating machine for more than four hours per day, wear hearing protection. Wear PPE during operation works at all time. As specified in Safety procedures.
4.23- Safety Precautions For Guarding Against Static Electricity And Gaseous Ignition
Polyethylene plastic pipe does not readily conduct electricity. A static electricity charge can buildup on inside and outside surfaces and stay on the pipe surface until some grounding device, such as a tool or a person comes close enough for the static electricity to discharge to the grounding device.
Discharging one part of the pipe surface will not affect other charged areas because static electricity does not flow readily from one area to another. Polyethylene pipe cannot be discharged by attaching grounding wires to the pipe. Heaters, electric facers and electric power tools are NOT explosion proof. Static electricity discharge can ignite a flammable gas or combustible dust atmosphere. A static electricity discharge to a person, a tool, or a grounded object close to the pipe surface can cause an electric shock or a spark that can ignite a flammable gas or combustible dust atmosphere causing fire or explosion. In gas utility applications, static electricity can be a potential safety hazard. Where a flammable gas-air mixture may be encountered and static charges may be present, such as when repairing a leak, squeezing-off an open pipe, purging, making a connection, etc., arc preventing safety precautions are necessary. Observe all procedures for static electricity safety and control, including procedures for discharging static electricity and requirements for personal protection. Take steps to discharge static electricity from the surface of the polyethylene gas pipe. Such steps include wetting the entire exposed pipe surface with a conductive anti-static liquid or a dilute soap and water solution, then covering or wrapping the entire wetted, exposed pipe surface with grounded wet burlap, conductive poly film, or wet tape conductor. The external covering should be kept wet by occasional rewetting with anti-static solution. The covering or tape should be suitably grounded such as to a metal pin driven into the ground.
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METHOD STATEMENT for HPDE
Steps that discharge the outer surface do not discharge the inner surface of the pipe. Squeeze-off purging, venting, cutting, etc., can still result in a static electricity discharge. When appropriate, ground tools and remove all potential sources of ignition.
Key items: Do not put a butt fusion machine chassis in a hazardous environment. Set the chassis up out of harm’s way and use extension hoses to operate upper works in hazardous area. Do not use a butt fusion machine with an electric facer in a gaseous environment. Use a machine equipped with a hydraulic facer or convert the electric facer to a manual by removing the brushes and turning facer manually. When making butt fusions, saddle fusions and socket fusions in a hazardous environment, set the generator up out of harm’s way and have the heater plugged into it there. Set the heater temperature at the maximum allowed for the application. Use 450° F for butt fusion and 510° F for saddle fusion and socket fusion. These are surface temperatures. The high side temperatures are used to compensate for the drop in temperature experienced when heater is unplugged from the power source to make fusion in hazardous area. Unplug heater prior to using in a hazardous environment. Do not drill hole first prior to making a saddle fusion. When prepping the main pipe for a saddle fusion, do not use an electric grinding tool. Prepare main pipe manually by use of 50-60 grit utility cloth. Do not use an electric drill for punching hole through after saddle fusion has been made. Use your senses and good judgment: Listen, Smell, Feel, See and Report any unsafe situations you see or see coming to your onsite , if corrective action is not taken in your opinion, Do not enter into the situation.
5- QUALITY CONTROL Quality fusion requires all of the required tools and equipment, and following all of the steps in the procedure in the correct sequence. The fusion procedure prepares and aligns the surfaces, heats the mating surfaces to the proper melt consistency, s the surface together under pressure, then cools the t under pressure. Faulty fusion is caused by improper or defective equipment, omitting steps or doing things out of the sequence. Faulty fusion may be hazardous. Training and experience provide knowledge and proficiency in what to do, what to expect, and recognizing potential problems in advance. Inadequately trained or in experienced persons
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METHOD STATEMENT for HPDE
can produce poor quality fusions, and they may expose themselves or other to hazards. Federal safety regulations require that persons making ts in gas system must be qualified in the pipeline operator’s qualified fusion procedures. They factors below are necessary for quality fusions are:
Use Personal Safety Equipment. Always wear a hard hat and protective boots. Gloves protect hands from heater burns and sharp blades on the facer. Protective Eye Glasses are also a good idea.
Make sure all equipment is in good working order and power cords are free of cuts with grounding blade on receptacle in tack.
Position fusion equipment on level ground whenever possible.
If the fusion equipment has wheels, set the wheel lock or block them.
Position pipe stands on either side of the fusion equipment approximately 20’ from ends of the fusion equipment. Adjust stands so that pipes are level to reduce drag.
Plug heater in on self-contained fusion units only after unit has been started and warmed up. Unplug heater before turning fusion unit off. This will keep you from having heater element and circuitry problems with your heater.
Load loose pipe ts into movable side of the fusion equipment and pull ts already fused through non-movable side.
Fusion tools and equipment must be correct for the job, and in proper working order.
Check your pipe before you fuse it. Look for deep scratches, cuts and gouges. Use the 10 percent rule: Any imperfection affecting more than 10 percent of the pipe wall being worked with should not be used.
When rough cutting pipe, use a pipe wrap to mark the pipe with a reference line, this will aid you in making a square and even cut. In general, tooling that works with wood works well with HDPE pipe. For cutting pipe, skill saws and chain saws work well. When using chain saws, the cut ends MUST be cleaned with isopropyl alcohol to remove BAR Oil Splash or any other contaminants. For cutting holes in pipe, drills with hole saws and reciprocating saws work well.
When making fusions that involve pipe to fittings, special care should be taken. The necking down or toe in at the pipe ends, which is normal, needs to be completely removed in the facing process. This is seen primarily in working with the larger pipe diameters.
The fusion operator must be proficient in tool and equipment use and operation, and proficient in fusion procedure.
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Do not abuse the facer when facing pipes by using too much pressure.
When pulling pipe through the fusion equipment, elevate pipe in the machine using the pipe lifts so the fusion bead clears all obstructions as it is pulled through
If a fusion weld does not come out exactly as you like or you question the quality of the fusion weld, then cut it out and re-fuse. Always – IF IN DOUBT, CUT IT OUT and redo.
Pipe and fitting surface must be clean and properly prepared.
Fusion beads can be removed by means of external and internal bead removers without effecting the integrity of the fusion t.
In inclement weather and especially in windy conditions, the fusion operation should be shielded to avoid precipitation or blowing snow and excessive heat loss from wind chill. Capping ends of pipe that are being fused aides heater from being chilled as fusion t is being made.
The t area and its parts that are being fused must be completely dry. No liquid of any kind running through the pipe or fittings is permissible.
When fusion is done in cold weather, DO NOT INCREASE HEATING TOOL SURFACE TEMPERATURE.
Do not try to shorten cooling times of fusions by applying wet cloths, water or the like.
Heating tool surfaces must be clean, undamaged and at the correct surface temperature.
When removing pipe from the fusing unit and pulling into place, use proper lifting slings and pulling heads in good condition. Chains and rope can slip and cause injury/damage to personnel and pipe.
When working with coiled pipe 2” - 6”, a McElroy Line Tamer™ should be used to straighten and re-round coiled pipe to meet or exceed ASTM D- 2513 Quality Requirements.
Squeeze tools can be used on HDPE Pipe to stop flow in a pipeline while a tie in or repair is made. Follow manufacturer’s squeeze-off tool instructions.
A common obstacle when working with HDPE pipe in the field is understanding the thermal expansion and contraction. Rule of thumb - 1.4”/ 100’/ 10ºF.
6- STORAGE & HANDLING 6.1-
Storage Method Statements must be approved for the transportation, handling and storage of pipes before any pipes are delivered to site.
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METHOD STATEMENT for HPDE
All pipes shall be handled and stored in compliance with the manufacturer's recommendations subject to the following limitations Pipes shall be transported, handled and stored with such packing and in such a manner that damage does not occur and that is avoided with sharp edges which may cause damage. During transit, pipes and fittings shall be well secured and adequately ed along their length. At every point of loading or unloading, all pipes or castings must be handled by approved lifting tackle unless specified elsewhere. Unloading by rolling down planks or any other form of inclined ramp will not be allowed. Pipes shall not be tipped or dropped. Pliable straps, slings or rope shall be used to lift pipes, and steel cables or chains will not be used without written permission. Nesting of pipes for transportation will be permitted provided method statements demonstrate that effective precautions will be taken to protect inner surfaces from damage. All pipes and fittings shall be thoroughly inspected on arrival at site after off-loading and prior to installation for detection of any damages. Damages to coatings, if any, shall be made good in an approved manner. For other damages, proposals for repairs shall be submitted in writing for the Engineer's approval. If in the Engineer's opinion the nature of any damage is such that the condition of a pipe has been impaired and cannot be repaired, the pipe concerned shall not be incorporated in the Works. Suitably smooth and level storage areas shall be provided at or near the site and made secure to prevent unauthorized access. Pipes of different sizes and thickness shall be stocked separately
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6.2-
Handling (Lifting) Each site will establish Safe Operating Procedures (SOP’s) for receiving, off-loading, and storage of HDPE pipe to ensure that: • A load inspection checklist has been completed to the load has been shipped according to company shipping requirements. These requirements are Intranetposted document is the controlled copy. printed document is still current prior to use • An HDPE Pipe Unloading Checklist (See Appendix D) is completed for loading or off- loading prior to beginning the task. • A 50-foot safe zone around the truck is established and marked, and a safety watch is in place to keep people out of the unloading/loading zone. The truck driver will remain with the safety watch until the off-loading is complete. • Site trucks/trailers used to move pipe sticks are equipped with engineered stints or other engineered means of securing the load. • Barriers or other means of preventing a line of fire issue are in place when unstrapping a load, such as using a loader with forks to block the load. • The site must ensure that equipment has been evaluated to ensure adequate lifting capacity and that the person operating the equipment is aware of the limitations. • Employees handling pipe have documented pipe handling task training. • Receiving or warehouse personnel coordinate the safe arrival of the shipping truck with the operations employees, and trucks will not be off-loaded until proper loading is verified utilizing the loading guidelines and the Load Inspection Checklist. If a truck is not loaded properly, the load will be rejected or an exemption and engineering review will be completed prior to off-loading. • A signed copy of the Load Inspection Checklist will be sent with the driver and presented to operations employees (or persons unloading) prior to unloading.
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• HDPE pipe is stored no more than two pipes high for 10” diameter or larger pipe, and no more than two feet for smaller diameter pipe, unless there are engineering controls in place to control the possibility of a stack collapsing. • An HDPE Pipe Permit will be completed prior to pulling/moving pipe. • Each site will establish SOP’s for pulling/moving of HDPE pipe. • All equipment used for pipe pulling/moving will meet the load specifications in DYNAMIC INDUSTRIAL ENGINEERING PROCEDURE • For 12” diameter pipe and larger Rigging and pulling procedures for pipe less than 12” diameter will be defined in site SOP’s. • For pulling or moving pipe less than 12” diameter and longer than 400 feet in length, an engineering review must be conducted and safe practices must be written into that SOP. • The use of a sling as a “choker” is NOT acceptable for pulling/moving an HDPE pipeline of a diameter 12” or larger unless an exemption is approved. This includes pulling lengths of pipeline while fusing in a fusing lay down area. It is however, acceptable to use a sling to lift and position pipe (i.e. positioning a pipeline in a fusing machine or removing it from the fusing machine). Intranet-posted document is the controlled copy. printed document is still current prior to use • Pipe-slotting, or cutting a slot or shape in the pipeline, to be used as an anchor point for pulling/moving an HDPE pipeline of a diameter 12” or larger is NOT acceptable unless an exemption is approved. • All ground personnel must be positioned out of the line of fire when pipe is being pulled or moved. If the minimum distance of 50 feet cannot be met, then substantial barriers must be utilized. • Safety watchers and blockers will be established for pulling/moving of pipe on haul roads or where there is potential f or interaction with other traffic as determined by risk assessment of the task. • HDPE pipe pulls will NOT exceed grades greater than 17.5% without an approved exemption. • Escorts and trailing vehicles must be used if pipe pulling occurs in active mining areas. Scheduling and communication of pipe movement activities must be completed.
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METHOD STATEMENT for HPDE
7- INSTALLATION INSTRUCTIONS 7.1-
Work Flow Chart
Inspection Pipe Storage
Pipe Delivery
Preparation
Pipe
for Welding
Alignment
Welding
Inspection
Process
and Report
7.2-
Pipe Handling
Pipe Laying
Pressure test
Equipment and Special Tools
Generator to supply the heater plate, trimmer and hydraulic pump.
Butt-fusion machine fitted with the correct size clamp shells, trimmer, heater plate, hydraulic pump and timer.
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Pipe rollers
Welding tent
Cleaning material, lint free cotton cloth or paper towel
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7.3-
External/Internal de-beading tool
Bead gauge
Digital thermometer with surface probe to check heater plate.
Pipe end covers
Baseboard
Pipe cutters
Air temperature thermometer
Indelible marker pen
Timer.
Before Start
Inspect pipe length and fittings for unacceptable cuts, gouges, deep scratches or other deleterious defects. Damage productions should not be used.
Toe-in or necking down is normal at pipe end, but may need to be removed for butt fusion to fittings. Ensure toe-in does not result in excess wall misalignment.
Remove Surface damage at pipe ends that could compromise the ing surface or interfere with fusion tools or equipment.
Be sure all required tools and equipment are on site, in proper working order and fueled up.
The pipe and fitting surface where tool and equipment are fitted must be clean and dry. USE CLEAN, dry, non-synthetic (Cotton) cloths or paper towels to remove dirt, sand and other contamination.
Shield heated fusion equipment and surfaces from inclement weather and winds. A temporary shelter over fusion equipment and the fusion operation may be required.
Relieve tension in the line before making connections.
Pipe must be correctly aligned before making connections.
8- APPLICATIONS 8.1-
Welding Conditions
Wind and Precipitation - Heating tool shall be shielded in insulated container to prevent excessive heat loss. Shield the pipe fusion area and fusion tools from wind, snow, blowing dust and rain by using a canopy or
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similar device. Open pipe ends should be covered with plugs or covers to protect the heater from unacceptable temperature variations. Protective measures with auxiliary heating is recommended when temperatures are below -4°F (-20°C).
Pipe and Fitting Surface Preparation – The pipe and fitting surfaces to be “ed” or held in clamps shall be dry and clean and free of ice, frost, snow, dirt, and other contamination. After regular procedure for facing, the surface shall be protected from contamination until ed
Heating – Check the temperature of the heating tool regularly with a pyrometer or other surface temperature measuring devise. Do not increase heating tool temperature above the specified temperature (450°F - 232°C) setting. Work quickly once pipe and fittings have been separated from the heating tool; so that melt heat loss is minimized, but still take time (no more than 3 seconds) to inspect both melt patterns. When the ambient temperature becomes colder, it will require a longer Heating time to develop an indication of melt and the final bead size.
Pre-Heating – When the ambient temperature is below 3°F (-16°C), the pipe ends shall be pre-heated using a heating blanket or warm air device to elevate the pipe temperature to improve the heating starting condition. With pipe mounted in the fusion machine, an alternate method of pre-heating is to stop the pipe ends within .25-.50 inches (6.4-12.7mm) of the heater plate face to allow the pipe ends to warm for 30 seconds to 2 minutes, depending on the pipe size and wall.
8.2-
Pipe Alignment The pipes must be aligned when they are clamped into the mirror welder in such a way that the surfaces are in the same plane (parallel) to each other. The HDPE pipes can be positioned directly into the welding machine. Install the correct adapter insert for the size of pipe diameter to be used and tighten them to the machine. Position the pipe in a way that approx. 40mm is protruding behind the last clamp. By doing this, you will have approx. 10 to 15mm to shave from, and the remaining 25 to 30 mm should be sufficient for welding. Once the pipe has been placed in position, the top clamps can be closed. It is important to tighten the top clamp nuts evenly in order to get a totally circular pipe, an even clamping pressure must be achieved. Then, make the first dry matching (press the two pipes to each other) and check the amount of shaving that will be required
8.3-
Welding Preparation
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The welding zone must be protected from unsuitable weather conditions (e.g. humidity effects, wind and temperatures below 0°C). The surfaces to be ed must be undamaged and free from impurities or loose particles. The manufacturer of the HDPE pipe should be asked to supply specific Recommendations for welding of their products or materials. Likewise, the welding machine supplier shall supply detailed welding procedure for their machines. Heat fusion bonding is a combination of temperature and force resulting in two mating surfaces flowing together to produce a t. Fusion bonding occurs when the t cools below the melt temperature of the material. There is a temperature range within which any particular material may be satisfactorily ed. The specified temperature used requires consideration of the properties of the specific material, the fusion equipment being used and the welding environment. The butt-welding is done in several phases and by using several parameters. The operations can be summarized as follows: - The alignment of the pipe - The shaving of the surfaces of the pipe ends - Cold matching of the HDPE pipes - Cleaning of surfaces - Heating of surfaces - Fusion of surfaces - Cooling of weld t The parameters used during welding are: - Bead-up pressure in bars or psi - Bead-up height in mm or inches - Heat soaking time in seconds - Heat soaking pressure in bars or psi - Transfer time in seconds - Fusion pressure in bars or psi - Cooling time in minutes These parameters are for information only and shall be compared with the parameters given by the HDPE pipe manufacturer and the welding machine supplier.
8.4-
Welding Parameters After the dry matching is completed, open up the pipes and introduce the shaver. Turn the shaver on and adjust to suitable speed. Press the two pipes together, and shave until a continuous strip of HDPE is peeling off on both sides of the shaver. Once constant peeling off is observed, release the pressure on the pipes and
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separate the pipes. Do not turn off the shaver until the pipes are apart. If the shaver is stopped during shaving, the shaver will create an end cut-mark and the shaving operation will have to be repeated. Remove the shaver, match the pipes again, and check the pipe for proper alignment. Sometimes, even when continuous peeling off is achieved on each side of the shaver, the pipes do not match properly. This is normally due to the clamps, which are pressing on to the pipe with different pressures. Re-tightening the nuts slightly on either side is one solution. But, if this does not help, shimming normally does the job. Open up one clamp and insert a shim in between the jaws and the pipe. This shim will concentrate the pressure on to the pipe and move the pipe into alignment. It is important to that, if the clamp has been opened during operation, the shaving operation must be repeated. Once the pipes are correctly aligned, separate the pipes again for cleaning. Remove chips inside the pipes on both sides, all chips scattered under the pipes, and also inside the machine. Otherwise, they will stick to the mirror (heat plate) later while reheating. Remove the chips by using a brush or a small hook made out of a thin steel wire. Never put any dirty gloves inside the pipe or remove the chips with your hands. Do not touch the shaved pipe ends. To be on the safe side, always clean the surface with a clean rag and mineral spirits/alcohol before you introduce the mirror.
8.5-
Heating the Surface Heating TOOI surface Temperature -4250F -E 250F (2180C 140C) Heating tool surfaces must be up to temperature before fusion begins. Prior to starting, all points on both heating tool surfaces where the heating tool surfaces will the pipe or fitting ends must be within the prescribed temperature range. The temperature difference between any two points on the heating tool fusion surfaces must not exceed 20"F (11 'C) for equipment for pipe smaller than 18-in (450 mm) diameter, or 35"F (19eC) for larger equipment. Heating tool surfaces must be clean. For heavy wall pipe (wall thickness z 1.5'), it is preferable to be in the lower half of the allowable temperature range. When the properly heated mating surfaces are brought together, the force required to make the t is the force that is necessary to roll the fusion melt beads over to the pipe surface. This is determined visually.
Drag Pressure Pressure ing Pressure
Variable 30+/- 5 psi (172 +/- 35 kPa) 25 – 90 psi (172 – 620 kPa) for pipe < 1.5” 25 – 50 psi (172 – 345 kPa) for pipe > 1.5”
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Interfacial Pressures
Required interfacial pressure is used as the basis for calculating the hydraulic pressure for a hydraulic butt fusion machine, or the applied force (measured using a torque wrench) for a manual machine, Interfacial pressures vary based on whether the pipe wall is considered 'heavy (1.5") or not. The correct hydraulic fusion ing pressure settings are calculated based on the type of butt fusion machine as well as the pipe OD and DR. The following formula is used to calculate the required hydraulic pressure on a butt fusion machine.
2
HP =
2
0.785 X ( OD - ID) X IP + DP PA
Where:
OD = Outside Diameter (in)
ID
= Inside Diameter (in)
IP
= Interfacial Pressure (psi)
PA = Piston Cross Sectional Area (in2)
DP = Drag Pressure (psi)
For hydraulic machines, the interfacial pressure, the fusion surface area, the machine's carriage cylinder size and internal drag pressure, and if necessary, the pressure needed to overcome external drag resistance, are used to calculate hydraulic pressure required. The equipment manufacturer's instructions can be used as a guide to calculate the drag pressure value. Interfacial pressure and fusion machine hydraulic fusion ing pressure gauge settings are not the same! For every fusion t, the system drag force must be measured to assure the proper compensation is applied to the fusion force. In most cases, the system drag will be the inherent drag in the hydraulic components of the machine for which the manufacturer will have a recommended value to use. However, to assure this had not changed due to the system set-up (ground slope or length of pipe being moved), it
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should be checked using the following procedure Slowly adjust upward the machine hydraulic control, or slowly increase torque on manually operated machines, to initiate carriage movement. The System Crag Pressure is the gauge pressure at which the carriage starts to move on hydraulic fusion machines. The System Drag Force is the observed force or torque at which the carriage starts to move on manually operated fusion machines. Repeat this measurement to the observed reading, Procedure allows for pipes to be misaligned up to of the minimum wall thickness. It is also allowable to fuse pipes of unequal dimension ratios, as long as the pipes are within one standard DR increment of each other. However, fusing two different DR's requires that the misalignment be no greater than 10% of the minimum wall thickness of the thinner walled pipe. Before you introduce the mirror, you should have all parameters available for this operation. Also check the mirror temperature. Normally, the mirror has a yellow or red lamp, which tells you if the mirror has reached working temperature. To make sure there is no cold air flowing through the pipe, place some plastic bags on each end of the pipe, this will prevent the air from cooling the mirror on one side. You have now shaved the pipe in to a good fit and removed the shaver and introduced the mirror. Push the pipes together against the mirror and raise the pressure to the Bead-up pressure. This pressure needs to be maintained until the Bead-up height has been reached. The bead up height is the height of the bead, which is pres against the mirror. As soon as the Bead up height has been reached, release the pressure down to the Heat Soak pressure. Heat soak pressure is the pressure maintained during the Heat Soak time. As soon as the heat soak time has elapsed, separate the pipes, remove the mirror, and then press together. 8.6-
Fusion the Surface This operation has to be done quite fast, since there is actually a time limit “Transfer time” from the removal of the mirror until the two pipes are pressed together and reached the Fusion pressure. Fusion pressure is the pressure that shall reach during the Transfer time and maintained during the Cooling time. Secure. Clean the inside and outside Of the component (pipe or fitting) ends by wiping with a clean, dry, lint-free cloth or paper towel remove all foreign matter. Align the components with the machine, place them in the clamps and then close the clamps. Do not force pipes into alignment against open fusion machine clamps. (When working with coiled pipe, f possible "S" the pipes on each side of the machine to compensate for coil curvature and make it easier to .) Component ends should protrude past the clamps enough so that facing will be complete. Bring the ends together and check high-low alignment, Adjust alignment as necessary by tightening the high side down.
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Face. Place the facing tool between the components ends, and face them to establish smooth, clean, parallel mating surfaces. Complete facing produces continuous circumferential shavings from both ends. Face until there is a minimal distance between the fixed and moveable clamps. Some machines have facing stops. If stops are present, face down to the stops. Remove the facing tool and clear all shavings and pipe chips from the component ends. Do not touch the component ends with your hands after facing. Align. Bring the component ends together, check alignment and check for slippage against fusion pressure. Look for complete all around both ends with no detectable gaps, and outside diameters in high-low alignment (except for the misalignment permitted in section 6.1). If necessary, adjust the high side by tightening the high side clamp. Do not loosen the low side clamp because components may slip during fusion. Re-face if high low alignment is adjusted. Melt. that the heating tool is maintaining the correct temperature. Place the heating tool between the component ends, and move the ends against the heating tool. The initial should be under moderate pressure (known as pressure) to ensure full . Hold pressure briefly then lower to drag pressure without breaking . pressure must be relieved at the first indication of melt completely around the pipe ends. Procedures for releasing the pressure in the hydraulic cylinder that creates interfacial pressure vary by manufacturer. Review the equipment manufacturers recommended procedure to ensure that only drag pressure is applied during the soak cycle. Hold the ends against the heating tool using only drag pressure. Beads of melted polyethylene will form against the heating tool at the component ends. When the proper melt bead Size is formed (see Table 1), quickly separate the ends and remove the heating tool. During heating, the melt bead will expand out flush to the heating tool surface, or may cud slightly away from the surface. If the melt bead curls significantly away from the heating tool surface, unacceptable pressure during heating may be indicated. Table 1 — Melt Bead Sizes for Corresponding Pipe Sizes Approximate Melt Bead Size (Measure from the heater plate)
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1/32” – 1/16” (1 – 2mm) About 1/16" (2mm) 1/8" – 3/16” (3 – 5mm) 3/16” – ¼” (5 – 6mm) ¼” – 7/16” (6 – 11mm) About 7/16” About 9/16” About 9/16”
1-1/4" and smaller (40 mm and smaller) Above 1-1/4" throu h 3" above 40 mm throu h 90mm Above 3" throu h B" above 90 mm throu h 225 mm Above g" throu h 12" above 225 mm throu h 315 mm Above 12" through 24" (above 315 mm through 630 mm) Above 24" throu h 36" above 630 mm throu h 915 mm Above 26" throu h 54" above g 15 mm throu h 1300 mm Above 54"
. Immediately after heating tool removal. QUICKLY inspect the melted ends, which should be flat, smooth, and completely melted. If the melt surfaces are acceptable. Immediately and in a continuous motion, bring the ends together and apply the correct ing pressure. Do not slam. Where the equipment permits, 'ramping up' to the ing pressure is desirable. Apply enough ing pressure to roll both melt beads over to the pipe surface A concave melt surface is unacceptable; it indicates pressure during heating. Do not continue. Allow the component ends to cool and start over again. The Correct ing pressure will form a double bead that is rolled over to the surface on both ends.
8.7-
Holding. Cooling time is the time in which the pipe has to be left undisturbed. Under no circumstances shall the clamps be opened or the pressure released until the cooling time has elapsed. Hold ing pressure against the ends until the t is cool. The t is cool enough for GENTLE handling when the double bead is cool to the touch. Cool for about 30 — 90 seconds per inch of pipe diameter. Do not try to shorten cooling time by applying water, wet clothes or the like. Avoid pulling, installation, pressure testing and rough handling for at least an additional 30 minutes. Heavier wall thickness pipes require longer cooling times. Inspect. On both sides, the double bead should be rolled over to the surface, and be uniformly rounded and consistent in size all around the t. As illustrated in Figure 3, the double bead width should be 2 to 2-1/2 times its height above the surface, and the v-groove depth between the beads should not be more than half the bead height. When butt fusing to molded fittings, the fittings side bead may have an irregular appearance, this is acceptable provided the pipe side bead is correct.
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It is not necessary for the internal bead to roll over to the inside surface of the pipe. When butt fusing pipe of dissimilar polyethylene materials, melt bead size may vary due to differences in melt index. This is acceptable provided the melt bead size is sufficient. The fusion t must be kept under fusion pressure until t has sufficiently cooled. Maintain fusion pressure against the piping component ends for a minimum of 11 minutes per inch (25.4mm) of pipe wall. Avoid high stress such as pulling, installation or rough handling for an additional 30 minutes or more after removal from the fusion machine
9- INSPECTION 9.1-
Welding Checks The double bead should be rolled over onto the adjacent surfaces, and be uniformly rounded and consistent in size all around the t. As illustrated in the Figure below, all beads will not necessarily have equal size. The cleavage between the beads must not be lower than the wall of the pipe as shown in the lower right illustration. When butt fusing pipe to molded fittings, the fitting side bead may have an irregular appearance. This is acceptable provided the pipe side bead is correct. It is not necessary for the internal bead to roll over to the inside surface of the pipe. When butt fusion pipe of dissimilar polyethylene materials, melt bead size may vary due to differences in melt index. This is acceptable provided the melt bead size is sufficient. The mirror-welding machine, if coupled to a data log, will give a printout confirming the parameters used during welding of a specific seam and approval/rejection of the welded seam.
9.2-
Defects & Causes BUTT FUSION TROUBLESHOOT DEFECTS CAUSES Excessive double bead width Overheating Excessive ing force Double bead v-groove too deep Excessive ing force Insufficient heating Pressure during heating Flat top on bead Excessive ing force Overheating Non-uniform bead size around pipe Misalignment Defective heating tool Worn equipment Incomplete facing
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One bead larger than the other
Beads too small Bead not rolled over to surface
Beads too large Square type outer bead edge Rough, Sandpaper like, bubbly or pockmarked melt bead surface
9.3-
Misalignment Component slipped in clamp Worn equipment Heating iron does not move freely in the axial direction Defective heating tool Incomplete facing Also possible when fusing bimodal pipes to uni-modal pipes Insufficient heating Insufficient ing force Shallow v-groove – Insufficient heating & insufficient ing force Deep v-groove – Insufficient heating & excessive ing force Bead on bimodal pipe may have slight gap to the pipe surface Excessive heating time Pressure during heating Hydrocarbon (gasoline vapors, spray paint fumes, etc.) contamination
Rules for Butt Weld Fusion NEVER • Attempt to weld together pipes of different SDR (wall thickness). • Touch trimmed pipe ends. • Leave trimming swarf inside pipe or on welding machine. • Allow equipment to get wet or dusty. • Use non-approved machinery. • Remove a weld from the machine before cooling time has elapsed. • Allow untrained personnel to use welding equipment. • Cut corners in any part of the welding procedure. • Weld pipes of different material on site (In factory controlled conditions it may be possible to do this). • Use a generator of inadequate capacity
9.4-
Report. Fill out the Pre-weld and after Weld Inspection check list and report as attached with ITP for HDPE Butt Weld Fusion. Prepare a log sheet to maintain calibration history of all equipment. Ensure tool box talk is carried out and briefed to all workers special to operators and welders before start the work.
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10- PRESSURE TESTING 10.1- Pressure Testing Outside the Trench: If specified by the engineer, pressure testing may be conducted prior to pipe installation. After the pipe has been ed, fill it with water, carefully bleed off any trapped air. Subject the pipe to a hydrostatic test pressure that is 1.5 times the system design pressure for a maximum of 3 hours. During this time, add water periodically to maintain the test pressure; this compensates for the initial stretching of the pipe. The line pressure tightness is determined by visual observation; therefore, it is not necessary to measure the make-up water. Examine every fused t; any leakage must be repaired and then retested. NOTE: It shall be the responsibility of the contractor to ensure that appropriate safety precautions are observed during hydrostatic testing above ground.
10.2- Pressure Testing Inside the Trench: Fill the pipeline with water after it has been laid; bleed off any trapped air. Subject the lowest element in the system to a test pressure that is 1.5 times the design pressure, and check for any leakage. When, in the opinion of the engineer, local conditions require that the trenches be backfilled immediately after the pipe has been laid, apply the pressure test after backfilling has been completed but not sooner than a time which will allow sufficient curing of any concrete that may have been used. Typical minimum concrete curing times are 36 hours for early strengths and 7 days for normal strengths. The test procedures consist of two steps; the initial expansion and the test phase. When test pressure is applied to a water filled pipe, the pipe expands. During the initial expansion of the pipe under test, sufficient make-up water must be added to the system at hourly intervals for 3 hours to maintain the test pressure. After about 4 hours, initial expansion should be complete and the actual test can start. When the test is to begin, the pipe is full of water and is subjected to a constant test pressure of 1.5 times the system design pressure. The test phase should not exceed 3 hours, after which time any water deficiency must be replaced and measured. Add and measure the amount of make-up water required to return to the test pressure and compare this to the maximum allowance in the table below. An alternate leakage test consists of maintaining the test pressure (described above) over a period of 4 hours and then dropping the pressure by 10 psi (0.69 MPa). If the pressure then remains within 5% of the target value for 1 hour, this indicates there is no leakage in the system.
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NOTES: Under no circumstances shall the total time under test exceed 8 hours at 1.5 times the system pressure rating. If the test is not complete within this time limit (due to leakage, equipment failure, etc.), the test section shall be permitted to “relax” for 8 hours prior to the next test sequence. Air testing is not recommended. Additional safety precautions may be required. Above procedure taken from PPI Technical Report TR-31 by the Plastic Pipe Institute. If does not meet the engineering project requirement, a new and separate pressure procedure shall be prepared and followed.
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DYNAMIC INDUSTRIAL ENGINEEING LLC PROJECT
High-density polyethylene (HDPE) PIPE WORK
PROCEDURE FOR WELDING AND INSTALLATION -
5180.DE.P10.950.R0
Revision History 0
27/03/13
WasiUllah Zeeshan
HDPE PIPE WORK
QA-QC Mngr
Rev No
Date
Description
Prepared By
Bahadur Khan Managing Director
Approved By
Notice All rights reserved. These materials are confidential and proprietary of Dynamic Engineering. No part of these materials should be reproduced, published in any form by any means (electronic or mechanical, including photocopy or any information storage or retrieval system), nor should the materials be disclosed to third parties without express written authorization of Dynamic Engineering.
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TABLE OF CONTENTS
1. Scope & General Provisions 1.1 Scope 1.2 General (Overview) 1.3 Responsibilities 2. References 3. & Definitions 4. Safety First 4.1
Safety Alerts
4.2
Read and understand
4.3
General Safety
4.4
Wear Safety Equipment
4.5
Units with hydraulics
4.6
Heaters are not explosion proof
4.7
Electric motors are not explosion proof
4.8
Electric Safety
4.9
Crush Point
4.10
Facer Blades are sharp
4.11
Heater is hot
4.12
Fusion Procedure
4.13
Units with Gas Engine
4.14
Units with battery
4.15
Have tiers properly serviced
4.16
Periodically check Temperature
4.17
Fusion Tow Speed
4.18
Fusion Machine Positioning
4.19
Edge of Ditch
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4.20
Track-star Fusion machine
4.21
Track-Star machine towing
4.22
PPE
4.23
Guarding against static electricity and gaseous Ignitions
5. Quality Control 6. Storage & handling 6.1 Storage 6.2 Handling 7. Installation Instructions 7.1 Work Flow Chart 7.2 Accessories and Special tools 7.3 Before Start 8. Applications 8.1 Welding Conditions 8.2 Pipe Alignment 8.3 Preparation of Pipe Ends 8.4 Welding Parameters 8.5 Heating of Surface 8.6 Fusion of Surface 8.7 Holding 8.8 Cooling of Surface 9. Inspection 9.1 Welding Checks 9.2 Defects and Causes 9.3 Rules for Butt Weld Fusion 9.4 Report 10. Pressure Testing 10.1
Pressure Testing Outside the Trench
10.2
Pressure Testing Inside the Trench
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1- SCOPE & GENERAL PROVISION 1.1-
Scope The scope of this model specification is for municipal water pipelines which conform to AWWA standards. This model specification provides minimum requirements for HDPE pipe and fittings to be used in the design and construction of municipal pressure piping projects. This document describes the Safety, Quality, Inspection, Preparation and Welding Procedure of the polyethylene pipe & fittings by fusion weld, it is to insure that the welded t will perform equal to or greater than pipe. This section specifies high density polyethylene pipe (HDPE) and fittings for water utility use as indicated on the Drawings, and as specified herein. • Furnish, Install, and Test HDPE pipe as indicated and specified in this section, and as referred to in related sections, and the Drawings for the Project. • The primary installation method is burial. The means and methods, including the testing for acceptance shall conform to all applicable standards as noted herein with the intention of providing a leak-free system to the owner.
1.2-
General (Overview) In butt fusion ing, mating surfaces are prepared, mating faces are melted with a hot plate heater, the heater is removed, and the melted surface are pressed together and held under pressure. As the molten material cool, they mix and fuse into a permanent, (homogeneous) monolithic t. DYNAMIC INDUSTRIAL ENGINEERING LLC pipe fusion procedure require special tools & equipment for the size of pipe and fittings being ed.
1.3-
Responsibilities The following duties are not limited and will be added to those mentioned in QA Manual. Management – Shall review/approve all the procedures and are prepared as per engineering design requirements. Quality and safety is implemented, maintained and monitored systematically. Engineer – shall prepare all the procedures before commencing of work. Must Ensure/monitor/supervise all work is being carried out as per engineering design requirements. Must carry out tool box talk, Checks, Inspects and Reports to Project
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METHOD STATEMENT for HPDE
Manager or higher management. Must raise NCR if the work is fall out of the acceptable criteria. Keep follow-ups with the corrective actions. Welder – Shall Prepare the Weld t and keep welding parameters as specified in the welding procedure. Must follow safety measure and precautions strictly.
2- REFERENCES To the extent referenced in this specification section, the standards and documents listed below are included, and made a part of this specification. In the event of a conflict, the requirements of this specification section prevail. Unless otherwise specified, references to documents shall mean the latest published edition of the referenced document in effect at the bid date of the project. ANSI/AWWA • ANSI/AWWA C901-08 Polyethylene (PE) Pressure Pipe and Tubing, ½ In. (13 mm) Through 3 In. (76 mm) for Water Service • ANSI/AWWA C906-07 Polyethylene (PE) Pressure Pipe and Fittings, 4 In. (100 mm) Through 63 In. (1,600 mm), for Water Distribution and Transmission • ANSI/AWWA C651 Standard for Disinfecting Water Mains • AWWA M55 Manual of Water Supply Practices, PE Pipe–Design and Installation Plastics Pipe Institute, PPI • PPI Handbook of Polyethylene Pipe – 2009 (2nd • PPI TR-33 Generic Butt Fusion ing Procedure for Polyethylene Gas Pipe Edition) • PPI TR-34 Disinfection of Newly Constructed Polyethylene Water Mains • PPI TR-41 Generic Saddle Fusion ing Procedure for Polyethylene Gas Piping • PPI TN-42 Recommended Minimum Training Guidelines for PE Pipe Butt Fusion ing Operators for Municipal and Industrial Projects (2009) NSF • NSF / ANSI 61 Drinking Water System Components–Health Effects ASTM • ASTM F 714 Standard Specification for Polyethylene (PE) Plastic Pipe (SDRPR) Based on Outside Diameter • ASTM F905 Standard Practice for Qualification of Polyethylene Saddle-Fused ts • ASTM F 1055 Standard Specification for Electro fusion Type Polyethylene Fittings for Outside Diameter Controlled Polyethylene Pipe and Tubing • ASTM F 1290 Standard Practice for Electro fusion ing Polyolefin Pipe and Fittings • ASTM F 1412 Standard Specification for Polyolefin Pipe and Fittings for Corrosive Waste Drainage Systems
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• ASTM F1417 Standard Test Method for Installation Acceptance of Plastic Gravity Sewer Lines Using Low-Pressure Air • ASTM F 2164 Standard Practice for Field Leak Testing of Polyethylene (PE) Pressure Piping Systems Using Hydrostatic Pressure • ASTM F2206 Standard Specification for Fabricated Fittings of Butt-Fused Polyethylene (PE) Plastic Pipe, Fittings, Sheet Stock, Plate Stock, or Block Stock • ASTM D 2239 Standard Specification for Polyethylene (PE) Plastic Pipe (SIDRP) Based on Controlled Inside Diameter • ASTM D 2321 Standard Practice for Underground Installation of Thermoplastic Pipe for Sewers and Other Gravity-Flow Applications • ASTM F 2620 Standard Practice for Heat Fusion ing of Polyethylene Pipe and Fittings • ASTM D 2683 Standard Specification for Socket-Type Polyethylene Fittings for Outside Diameter-Controlled Polyethylene Pipe and Tubing • ASTM D 2737 Standard Specification for Polyethylene (PE) Plastic Tubing • ASTM D 2774 Standard Practice for Underground Installation of Thermoplastic Pressure Piping • ASTM D 3261 Standard Specification for Butt Heat Fusion Polyethylene (PE) Plastic Fittings for Polyethylene (PE) Plastic Pipe and Tubing • ASTM D 3350-08 Standard Specification for Polyethylene Plastics Pipe and Fittings Materials.
3- & DEFINATIONS
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OPI PPI AWWA ASTM FMS NSF HDPE PE PVC DI DIPS IPS CTS ID OD PSI PSI DR SDR PS WP 4- WPR MJ DIMJA NPT Tubing Perf FOB
Oxford Plastic Inc Plastic Pipe Institute American Water Works Association American Society of Testing and Materials Factory Mutual Standards National Sanitation Foundation High Density Polyethylene Polyethylene Poly Vinyl Chloride Ductile Iron Ductile Iron Pipe Size Iron Pipe Size Copper Tube Size Inside Diameter Outside Diameter Pounds Per Square Inch Pounds Per Square Inch Dimension Ratio Standard Dimension Ratio Pressure Surge Working Pressure Working Pressure Rating Mechanical t Ductile Iron Mechanical t Assembly National Pipe Thread HDPE Corrugated Tubing HDPE Perforated Corrugated Tubing Freight on Board
SAFETY FIRST 4.1-
Safet y
Alerts This hazard alert sign
Appears in this manual. When you see this sign,
carefully read what it says. YOUR SAFETY IS AT STAKE. You will see the hazard alert sign with these words: DANGER, WARNING, and CAUTION.
Indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
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Indicates a hazardous situation which, if not avoided, may result in minor or moderate injury. In this manual you should look for two other words: NOTICE and IMPORTANT. NOTICE: Can keep you from doing something that might damage the machine or someone’s property. It may also be used to alert against unsafe practices. IMPORTANT: Can help you do a better job or make your job easier in some way.
4.2-
Read and Understand Do not operate fusion equipment until you have carefully read, and understand the “Safety” and “Operation” sections of this manual, and all other equipment manuals that will be used with it. Your safety and the safety of others depends upon care and judgment in the operation of this equipment. Follow all applicable federal, state, local, and industry specific regulations
4.3-
General Safety DYNAMIC INDUSTRIAL ENGINEERIN LLC cannot anticipate every possible circumstance that may involve a potential hazard. The warnings in this manual and on the machine are therefore not all inclusive. You must satisfy yourself that a procedure, tool, work method, or operating technique is safe for you and others. You should also ensure that the machine will not be damaged or made unsafe by the method of operation or maintenance you choose. Safety is important. Report anything unusual that you notice during set up or operation. Listen For thumps, bumps, rattles, squeals, air leaks, or unusual sounds. Smell Odors like burning insulation, hot metal, burning rubber, hot oil, or natural gas. Sense Any changes in the way the equipment operates. See Problems with wiring and cables, hydraulic connections, or other equipment. Report
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Anything you see, feel, smell, or hear that is different from what you expect, or that you think may be unsafe
4.4-
Wear Safety Equipment Wear a hard hat, safety shoes, safety glasses, and other applicable personal protection equipment. Remove jewelry and rings, and do not wear loose-fitting clothing or long hair that could catch on controls or moving machinery.
4.5-
Units with Hydraulics Although the hydraulic pressures in the machine are low compared to some hydraulically operated equipment, it is important to that a sudden hydraulic leak can cause serious injury or even be fatal if the pressure is high enough. Escaping fluid under pressure can penetrate the skin causing serious injury. Keep hand sand body away from pinholes which eject fluid under pressure. Use a piece of cardboard or paper to search for leaks. If any fluid is injected into the skin, it must be immediately removed by a doctor familiar with this type of injury. NOTICE: Wear safety glasses, and keep face clear of area when bleeding air from hydraulic system to avoid spraying into eyes
4.6-
Heaters are Not Explosion Proof
Operation of a heater in a hazardous environment without necessary safety precautions will result in explosion and death. When operating in a hazardous environment, heater should be brought up to temperature in a safe environment, then unplugged before entering the hazardous atmosphere for fusion.
4.7-
Electric Motors are Not Explosion Proof
Electric Motors are not explosion proof. Operation of these components in a hazardous environment without necessary safety precautions will result in explosion or death. When operating in a hazardous environment, keep pump motor and chassis in a safe area by using hydraulic extension hoses
4.8-
Electric Safety
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Always ensure power cords are properly grounded. It is important to that when you are working in a wet environment with electrical devices, proper ground connections help to minimize the chances of an electric shock. Frequently inspect electrical cords and unit for damage. Damaged components need to replaced and service performed by a qualified electrician. Do not carry electrical devices by the cord.
NOTICE: Always connect units to the proper power source as listed on the unit, or in the owner’s manual. On units with two power cords, plug each cord into separate power circuits. Do not plug into both outlets of one duplex receptacle. NOTICE: Disconnect the machine from the power source before attempting any maintenance or adjustment
4.9-
Crush Points
Hydraulically operated jaws are operated under pressure. Anything caught in the jaws will be crushed. Keep fingers, feet, arms, legs, and head out of the jaw area. Always check pipe alignment with a pencil or similar object.
4.10- Facer Blades Are Sharp
Facer blades are sharp and can cut. Never attempt to remove shavings while the facer is running, or is in the facing position between the jaws. Use care when operating the facer, and handling the unit. NOTICE: Disconnect power from the facer, and remove the facer blades before attempting any maintenance or adjustment.
4.11-
Heater is Hot
The heater is hot and will burn clothing and skin. Keep the heater in its insulated heater stand or sling blanket when not in use, and use care when heating the pipe. NOTICE:
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Use only a clean non-synthetic cloth such as a cotton cloth to clean the heater plates
4.12- Fusion Procedure
Follow the procedures carefully, and adhere to all specified parameters. Failure to follow procedures could result in a bad weld. Always follow the proper fusion procedures.
4.13- Units With Gas Engines
Handle fuel with care. Fuel is highly flammable. Do not refuel the machine while smoking or near open flames or sparks. Always stop the engine before refueling machine. Fill fuel tank outdoors. Help prevent fires by keeping machine clean of accumulated trash, grease, debris, and facer shavings. Always clean up spilled fuel.
Breathing exhaust gases can cause sickness or death. Always operate machine outdoors in an area with adequate ventilation
4.14- Units with Batteries
Sulfuric acid in battery electrolyte is poisonous. It is strong enough to burn skin, eat holes in clothing, and cause blindness if splashed into eyes. Avoid with eyes, skin, and clothing. Exploding gases from battery could cause blindness or serious injury. Keep sparks, flames and cigarettes away.
4.15- Have Tiers Properly Serviced
Failure to follow proper procedures when mounting a tire on a wheel or rim can produce an explosion which may result in serious injury or death. Have tires mounted by someone that is experienced, and has the equipment to perform the job safely
4.16- Periodically Check Temperature NOTICE:
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Incorrect heating temperature can result in bad fusion ts. Check heater plate surface temperature periodically with a pyrometer, and make necessary adjustments. The thermometer on heaters indicates internal temperature, and should be used as a reference only
4.17- DO NOT Tow Fusion Machine
The chassis is not designed for over-road towing. Towing at speeds greater than (05) five miles per hour can result in machine damage as well as injury. Always transport the machine by flatbed truck or similar means, and make sure that unit is properly secured.
4.18- Position Fusion Machine Place fusion machine on as level ground as possible, and set the brake on the rear wheel. If it is necessary to operate machine on un-level grade, chock the wheels and block the unit to make it as stable as possible
4.19- Keep Machine Away from Edge of Ditch
Heavy equipment too close to a ditch can cause the walls of the ditch to cave-in. Keep the machine far enough away from the edge of the ditch to prevent injury to personnel and equipment from a cave-in
4.20- Operating Trac-Star Fusion Machines Place fusion machine on as level ground as possible. If it is necessary to operate machine on un-level grade, make sure that the ground is stable. Some unstable conditions maybe ice, snow, mud, and loose gravel.
For operation safety, never operate machine on a grade steeper than 30%. (A 3 foot elevation change in 10 feet.)
4.21- Do Not Attempt to Tow A Trac-Star Fusion Machine
The machine is not designed for towing. Attempting to tow the machine can result in machine damage. Always transport the machine by flatbed truck or similar means, and make sure that unit is properly secured.
4.22- Protective Equipment
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When operating machine for more than four hours per day, wear hearing protection. Wear PPE during operation works at all time. As specified in Safety procedures.
4.23- Safety Precautions For Guarding Against Static Electricity And Gaseous Ignition
Polyethylene plastic pipe does not readily conduct electricity. A static electricity charge can buildup on inside and outside surfaces and stay on the pipe surface until some grounding device, such as a tool or a person comes close enough for the static electricity to discharge to the grounding device.
Discharging one part of the pipe surface will not affect other charged areas because static electricity does not flow readily from one area to another. Polyethylene pipe cannot be discharged by attaching grounding wires to the pipe. Heaters, electric facers and electric power tools are NOT explosion proof. Static electricity discharge can ignite a flammable gas or combustible dust atmosphere. A static electricity discharge to a person, a tool, or a grounded object close to the pipe surface can cause an electric shock or a spark that can ignite a flammable gas or combustible dust atmosphere causing fire or explosion. In gas utility applications, static electricity can be a potential safety hazard. Where a flammable gas-air mixture may be encountered and static charges may be present, such as when repairing a leak, squeezing-off an open pipe, purging, making a connection, etc., arc preventing safety precautions are necessary. Observe all procedures for static electricity safety and control, including procedures for discharging static electricity and requirements for personal protection. Take steps to discharge static electricity from the surface of the polyethylene gas pipe. Such steps include wetting the entire exposed pipe surface with a conductive anti-static liquid or a dilute soap and water solution, then covering or wrapping the entire wetted, exposed pipe surface with grounded wet burlap, conductive poly film, or wet tape conductor. The external covering should be kept wet by occasional rewetting with anti-static solution. The covering or tape should be suitably grounded such as to a metal pin driven into the ground.
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Steps that discharge the outer surface do not discharge the inner surface of the pipe. Squeeze-off purging, venting, cutting, etc., can still result in a static electricity discharge. When appropriate, ground tools and remove all potential sources of ignition.
Key items: Do not put a butt fusion machine chassis in a hazardous environment. Set the chassis up out of harm’s way and use extension hoses to operate upper works in hazardous area. Do not use a butt fusion machine with an electric facer in a gaseous environment. Use a machine equipped with a hydraulic facer or convert the electric facer to a manual by removing the brushes and turning facer manually. When making butt fusions, saddle fusions and socket fusions in a hazardous environment, set the generator up out of harm’s way and have the heater plugged into it there. Set the heater temperature at the maximum allowed for the application. Use 450° F for butt fusion and 510° F for saddle fusion and socket fusion. These are surface temperatures. The high side temperatures are used to compensate for the drop in temperature experienced when heater is unplugged from the power source to make fusion in hazardous area. Unplug heater prior to using in a hazardous environment. Do not drill hole first prior to making a saddle fusion. When prepping the main pipe for a saddle fusion, do not use an electric grinding tool. Prepare main pipe manually by use of 50-60 grit utility cloth. Do not use an electric drill for punching hole through after saddle fusion has been made. Use your senses and good judgment: Listen, Smell, Feel, See and Report any unsafe situations you see or see coming to your onsite , if corrective action is not taken in your opinion, Do not enter into the situation.
5- QUALITY CONTROL Quality fusion requires all of the required tools and equipment, and following all of the steps in the procedure in the correct sequence. The fusion procedure prepares and aligns the surfaces, heats the mating surfaces to the proper melt consistency, s the surface together under pressure, then cools the t under pressure. Faulty fusion is caused by improper or defective equipment, omitting steps or doing things out of the sequence. Faulty fusion may be hazardous. Training and experience provide knowledge and proficiency in what to do, what to expect, and recognizing potential problems in advance. Inadequately trained or in experienced persons
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can produce poor quality fusions, and they may expose themselves or other to hazards. Federal safety regulations require that persons making ts in gas system must be qualified in the pipeline operator’s qualified fusion procedures. They factors below are necessary for quality fusions are:
Use Personal Safety Equipment. Always wear a hard hat and protective boots. Gloves protect hands from heater burns and sharp blades on the facer. Protective Eye Glasses are also a good idea.
Make sure all equipment is in good working order and power cords are free of cuts with grounding blade on receptacle in tack.
Position fusion equipment on level ground whenever possible.
If the fusion equipment has wheels, set the wheel lock or block them.
Position pipe stands on either side of the fusion equipment approximately 20’ from ends of the fusion equipment. Adjust stands so that pipes are level to reduce drag.
Plug heater in on self-contained fusion units only after unit has been started and warmed up. Unplug heater before turning fusion unit off. This will keep you from having heater element and circuitry problems with your heater.
Load loose pipe ts into movable side of the fusion equipment and pull ts already fused through non-movable side.
Fusion tools and equipment must be correct for the job, and in proper working order.
Check your pipe before you fuse it. Look for deep scratches, cuts and gouges. Use the 10 percent rule: Any imperfection affecting more than 10 percent of the pipe wall being worked with should not be used.
When rough cutting pipe, use a pipe wrap to mark the pipe with a reference line, this will aid you in making a square and even cut. In general, tooling that works with wood works well with HDPE pipe. For cutting pipe, skill saws and chain saws work well. When using chain saws, the cut ends MUST be cleaned with isopropyl alcohol to remove BAR Oil Splash or any other contaminants. For cutting holes in pipe, drills with hole saws and reciprocating saws work well.
When making fusions that involve pipe to fittings, special care should be taken. The necking down or toe in at the pipe ends, which is normal, needs to be completely removed in the facing process. This is seen primarily in working with the larger pipe diameters.
The fusion operator must be proficient in tool and equipment use and operation, and proficient in fusion procedure.
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Do not abuse the facer when facing pipes by using too much pressure.
When pulling pipe through the fusion equipment, elevate pipe in the machine using the pipe lifts so the fusion bead clears all obstructions as it is pulled through
If a fusion weld does not come out exactly as you like or you question the quality of the fusion weld, then cut it out and re-fuse. Always – IF IN DOUBT, CUT IT OUT and redo.
Pipe and fitting surface must be clean and properly prepared.
Fusion beads can be removed by means of external and internal bead removers without effecting the integrity of the fusion t.
In inclement weather and especially in windy conditions, the fusion operation should be shielded to avoid precipitation or blowing snow and excessive heat loss from wind chill. Capping ends of pipe that are being fused aides heater from being chilled as fusion t is being made.
The t area and its parts that are being fused must be completely dry. No liquid of any kind running through the pipe or fittings is permissible.
When fusion is done in cold weather, DO NOT INCREASE HEATING TOOL SURFACE TEMPERATURE.
Do not try to shorten cooling times of fusions by applying wet cloths, water or the like.
Heating tool surfaces must be clean, undamaged and at the correct surface temperature.
When removing pipe from the fusing unit and pulling into place, use proper lifting slings and pulling heads in good condition. Chains and rope can slip and cause injury/damage to personnel and pipe.
When working with coiled pipe 2” - 6”, a McElroy Line Tamer™ should be used to straighten and re-round coiled pipe to meet or exceed ASTM D- 2513 Quality Requirements.
Squeeze tools can be used on HDPE Pipe to stop flow in a pipeline while a tie in or repair is made. Follow manufacturer’s squeeze-off tool instructions.
A common obstacle when working with HDPE pipe in the field is understanding the thermal expansion and contraction. Rule of thumb - 1.4”/ 100’/ 10ºF.
6- STORAGE & HANDLING 6.1-
Storage Method Statements must be approved for the transportation, handling and storage of pipes before any pipes are delivered to site.
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All pipes shall be handled and stored in compliance with the manufacturer's recommendations subject to the following limitations Pipes shall be transported, handled and stored with such packing and in such a manner that damage does not occur and that is avoided with sharp edges which may cause damage. During transit, pipes and fittings shall be well secured and adequately ed along their length. At every point of loading or unloading, all pipes or castings must be handled by approved lifting tackle unless specified elsewhere. Unloading by rolling down planks or any other form of inclined ramp will not be allowed. Pipes shall not be tipped or dropped. Pliable straps, slings or rope shall be used to lift pipes, and steel cables or chains will not be used without written permission. Nesting of pipes for transportation will be permitted provided method statements demonstrate that effective precautions will be taken to protect inner surfaces from damage. All pipes and fittings shall be thoroughly inspected on arrival at site after off-loading and prior to installation for detection of any damages. Damages to coatings, if any, shall be made good in an approved manner. For other damages, proposals for repairs shall be submitted in writing for the Engineer's approval. If in the Engineer's opinion the nature of any damage is such that the condition of a pipe has been impaired and cannot be repaired, the pipe concerned shall not be incorporated in the Works. Suitably smooth and level storage areas shall be provided at or near the site and made secure to prevent unauthorized access. Pipes of different sizes and thickness shall be stocked separately
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6.2-
Handling (Lifting) Each site will establish Safe Operating Procedures (SOP’s) for receiving, off-loading, and storage of HDPE pipe to ensure that: • A load inspection checklist has been completed to the load has been shipped according to company shipping requirements. These requirements are Intranetposted document is the controlled copy. printed document is still current prior to use • An HDPE Pipe Unloading Checklist (See Appendix D) is completed for loading or off- loading prior to beginning the task. • A 50-foot safe zone around the truck is established and marked, and a safety watch is in place to keep people out of the unloading/loading zone. The truck driver will remain with the safety watch until the off-loading is complete. • Site trucks/trailers used to move pipe sticks are equipped with engineered stints or other engineered means of securing the load. • Barriers or other means of preventing a line of fire issue are in place when unstrapping a load, such as using a loader with forks to block the load. • The site must ensure that equipment has been evaluated to ensure adequate lifting capacity and that the person operating the equipment is aware of the limitations. • Employees handling pipe have documented pipe handling task training. • Receiving or warehouse personnel coordinate the safe arrival of the shipping truck with the operations employees, and trucks will not be off-loaded until proper loading is verified utilizing the loading guidelines and the Load Inspection Checklist. If a truck is not loaded properly, the load will be rejected or an exemption and engineering review will be completed prior to off-loading. • A signed copy of the Load Inspection Checklist will be sent with the driver and presented to operations employees (or persons unloading) prior to unloading.
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• HDPE pipe is stored no more than two pipes high for 10” diameter or larger pipe, and no more than two feet for smaller diameter pipe, unless there are engineering controls in place to control the possibility of a stack collapsing. • An HDPE Pipe Permit will be completed prior to pulling/moving pipe. • Each site will establish SOP’s for pulling/moving of HDPE pipe. • All equipment used for pipe pulling/moving will meet the load specifications in DYNAMIC INDUSTRIAL ENGINEERING PROCEDURE • For 12” diameter pipe and larger Rigging and pulling procedures for pipe less than 12” diameter will be defined in site SOP’s. • For pulling or moving pipe less than 12” diameter and longer than 400 feet in length, an engineering review must be conducted and safe practices must be written into that SOP. • The use of a sling as a “choker” is NOT acceptable for pulling/moving an HDPE pipeline of a diameter 12” or larger unless an exemption is approved. This includes pulling lengths of pipeline while fusing in a fusing lay down area. It is however, acceptable to use a sling to lift and position pipe (i.e. positioning a pipeline in a fusing machine or removing it from the fusing machine). Intranet-posted document is the controlled copy. printed document is still current prior to use • Pipe-slotting, or cutting a slot or shape in the pipeline, to be used as an anchor point for pulling/moving an HDPE pipeline of a diameter 12” or larger is NOT acceptable unless an exemption is approved. • All ground personnel must be positioned out of the line of fire when pipe is being pulled or moved. If the minimum distance of 50 feet cannot be met, then substantial barriers must be utilized. • Safety watchers and blockers will be established for pulling/moving of pipe on haul roads or where there is potential f or interaction with other traffic as determined by risk assessment of the task. • HDPE pipe pulls will NOT exceed grades greater than 17.5% without an approved exemption. • Escorts and trailing vehicles must be used if pipe pulling occurs in active mining areas. Scheduling and communication of pipe movement activities must be completed.
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7- INSTALLATION INSTRUCTIONS 7.1-
Work Flow Chart
Inspection Pipe Storage
Pipe Delivery
Preparation
Pipe
for Welding
Alignment
Welding
Inspection
Process
and Report
7.2-
Pipe Handling
Pipe Laying
Pressure test
Equipment and Special Tools
Generator to supply the heater plate, trimmer and hydraulic pump.
Butt-fusion machine fitted with the correct size clamp shells, trimmer, heater plate, hydraulic pump and timer.
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Pipe rollers
Welding tent
Cleaning material, lint free cotton cloth or paper towel
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7.3-
External/Internal de-beading tool
Bead gauge
Digital thermometer with surface probe to check heater plate.
Pipe end covers
Baseboard
Pipe cutters
Air temperature thermometer
Indelible marker pen
Timer.
Before Start
Inspect pipe length and fittings for unacceptable cuts, gouges, deep scratches or other deleterious defects. Damage productions should not be used.
Toe-in or necking down is normal at pipe end, but may need to be removed for butt fusion to fittings. Ensure toe-in does not result in excess wall misalignment.
Remove Surface damage at pipe ends that could compromise the ing surface or interfere with fusion tools or equipment.
Be sure all required tools and equipment are on site, in proper working order and fueled up.
The pipe and fitting surface where tool and equipment are fitted must be clean and dry. USE CLEAN, dry, non-synthetic (Cotton) cloths or paper towels to remove dirt, sand and other contamination.
Shield heated fusion equipment and surfaces from inclement weather and winds. A temporary shelter over fusion equipment and the fusion operation may be required.
Relieve tension in the line before making connections.
Pipe must be correctly aligned before making connections.
8- APPLICATIONS 8.1-
Welding Conditions
Wind and Precipitation - Heating tool shall be shielded in insulated container to prevent excessive heat loss. Shield the pipe fusion area and fusion tools from wind, snow, blowing dust and rain by using a canopy or
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similar device. Open pipe ends should be covered with plugs or covers to protect the heater from unacceptable temperature variations. Protective measures with auxiliary heating is recommended when temperatures are below -4°F (-20°C).
Pipe and Fitting Surface Preparation – The pipe and fitting surfaces to be “ed” or held in clamps shall be dry and clean and free of ice, frost, snow, dirt, and other contamination. After regular procedure for facing, the surface shall be protected from contamination until ed
Heating – Check the temperature of the heating tool regularly with a pyrometer or other surface temperature measuring devise. Do not increase heating tool temperature above the specified temperature (450°F - 232°C) setting. Work quickly once pipe and fittings have been separated from the heating tool; so that melt heat loss is minimized, but still take time (no more than 3 seconds) to inspect both melt patterns. When the ambient temperature becomes colder, it will require a longer Heating time to develop an indication of melt and the final bead size.
Pre-Heating – When the ambient temperature is below 3°F (-16°C), the pipe ends shall be pre-heated using a heating blanket or warm air device to elevate the pipe temperature to improve the heating starting condition. With pipe mounted in the fusion machine, an alternate method of pre-heating is to stop the pipe ends within .25-.50 inches (6.4-12.7mm) of the heater plate face to allow the pipe ends to warm for 30 seconds to 2 minutes, depending on the pipe size and wall.
8.2-
Pipe Alignment The pipes must be aligned when they are clamped into the mirror welder in such a way that the surfaces are in the same plane (parallel) to each other. The HDPE pipes can be positioned directly into the welding machine. Install the correct adapter insert for the size of pipe diameter to be used and tighten them to the machine. Position the pipe in a way that approx. 40mm is protruding behind the last clamp. By doing this, you will have approx. 10 to 15mm to shave from, and the remaining 25 to 30 mm should be sufficient for welding. Once the pipe has been placed in position, the top clamps can be closed. It is important to tighten the top clamp nuts evenly in order to get a totally circular pipe, an even clamping pressure must be achieved. Then, make the first dry matching (press the two pipes to each other) and check the amount of shaving that will be required
8.3-
Welding Preparation
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The welding zone must be protected from unsuitable weather conditions (e.g. humidity effects, wind and temperatures below 0°C). The surfaces to be ed must be undamaged and free from impurities or loose particles. The manufacturer of the HDPE pipe should be asked to supply specific Recommendations for welding of their products or materials. Likewise, the welding machine supplier shall supply detailed welding procedure for their machines. Heat fusion bonding is a combination of temperature and force resulting in two mating surfaces flowing together to produce a t. Fusion bonding occurs when the t cools below the melt temperature of the material. There is a temperature range within which any particular material may be satisfactorily ed. The specified temperature used requires consideration of the properties of the specific material, the fusion equipment being used and the welding environment. The butt-welding is done in several phases and by using several parameters. The operations can be summarized as follows: - The alignment of the pipe - The shaving of the surfaces of the pipe ends - Cold matching of the HDPE pipes - Cleaning of surfaces - Heating of surfaces - Fusion of surfaces - Cooling of weld t The parameters used during welding are: - Bead-up pressure in bars or psi - Bead-up height in mm or inches - Heat soaking time in seconds - Heat soaking pressure in bars or psi - Transfer time in seconds - Fusion pressure in bars or psi - Cooling time in minutes These parameters are for information only and shall be compared with the parameters given by the HDPE pipe manufacturer and the welding machine supplier.
8.4-
Welding Parameters After the dry matching is completed, open up the pipes and introduce the shaver. Turn the shaver on and adjust to suitable speed. Press the two pipes together, and shave until a continuous strip of HDPE is peeling off on both sides of the shaver. Once constant peeling off is observed, release the pressure on the pipes and
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separate the pipes. Do not turn off the shaver until the pipes are apart. If the shaver is stopped during shaving, the shaver will create an end cut-mark and the shaving operation will have to be repeated. Remove the shaver, match the pipes again, and check the pipe for proper alignment. Sometimes, even when continuous peeling off is achieved on each side of the shaver, the pipes do not match properly. This is normally due to the clamps, which are pressing on to the pipe with different pressures. Re-tightening the nuts slightly on either side is one solution. But, if this does not help, shimming normally does the job. Open up one clamp and insert a shim in between the jaws and the pipe. This shim will concentrate the pressure on to the pipe and move the pipe into alignment. It is important to that, if the clamp has been opened during operation, the shaving operation must be repeated. Once the pipes are correctly aligned, separate the pipes again for cleaning. Remove chips inside the pipes on both sides, all chips scattered under the pipes, and also inside the machine. Otherwise, they will stick to the mirror (heat plate) later while reheating. Remove the chips by using a brush or a small hook made out of a thin steel wire. Never put any dirty gloves inside the pipe or remove the chips with your hands. Do not touch the shaved pipe ends. To be on the safe side, always clean the surface with a clean rag and mineral spirits/alcohol before you introduce the mirror.
8.5-
Heating the Surface Heating TOOI surface Temperature -4250F -E 250F (2180C 140C) Heating tool surfaces must be up to temperature before fusion begins. Prior to starting, all points on both heating tool surfaces where the heating tool surfaces will the pipe or fitting ends must be within the prescribed temperature range. The temperature difference between any two points on the heating tool fusion surfaces must not exceed 20"F (11 'C) for equipment for pipe smaller than 18-in (450 mm) diameter, or 35"F (19eC) for larger equipment. Heating tool surfaces must be clean. For heavy wall pipe (wall thickness z 1.5'), it is preferable to be in the lower half of the allowable temperature range. When the properly heated mating surfaces are brought together, the force required to make the t is the force that is necessary to roll the fusion melt beads over to the pipe surface. This is determined visually.
Drag Pressure Pressure ing Pressure
Variable 30+/- 5 psi (172 +/- 35 kPa) 25 – 90 psi (172 – 620 kPa) for pipe < 1.5” 25 – 50 psi (172 – 345 kPa) for pipe > 1.5”
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Interfacial Pressures
Required interfacial pressure is used as the basis for calculating the hydraulic pressure for a hydraulic butt fusion machine, or the applied force (measured using a torque wrench) for a manual machine, Interfacial pressures vary based on whether the pipe wall is considered 'heavy (1.5") or not. The correct hydraulic fusion ing pressure settings are calculated based on the type of butt fusion machine as well as the pipe OD and DR. The following formula is used to calculate the required hydraulic pressure on a butt fusion machine.
2
HP =
2
0.785 X ( OD - ID) X IP + DP PA
Where:
OD = Outside Diameter (in)
ID
= Inside Diameter (in)
IP
= Interfacial Pressure (psi)
PA = Piston Cross Sectional Area (in2)
DP = Drag Pressure (psi)
For hydraulic machines, the interfacial pressure, the fusion surface area, the machine's carriage cylinder size and internal drag pressure, and if necessary, the pressure needed to overcome external drag resistance, are used to calculate hydraulic pressure required. The equipment manufacturer's instructions can be used as a guide to calculate the drag pressure value. Interfacial pressure and fusion machine hydraulic fusion ing pressure gauge settings are not the same! For every fusion t, the system drag force must be measured to assure the proper compensation is applied to the fusion force. In most cases, the system drag will be the inherent drag in the hydraulic components of the machine for which the manufacturer will have a recommended value to use. However, to assure this had not changed due to the system set-up (ground slope or length of pipe being moved), it
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should be checked using the following procedure Slowly adjust upward the machine hydraulic control, or slowly increase torque on manually operated machines, to initiate carriage movement. The System Crag Pressure is the gauge pressure at which the carriage starts to move on hydraulic fusion machines. The System Drag Force is the observed force or torque at which the carriage starts to move on manually operated fusion machines. Repeat this measurement to the observed reading, Procedure allows for pipes to be misaligned up to of the minimum wall thickness. It is also allowable to fuse pipes of unequal dimension ratios, as long as the pipes are within one standard DR increment of each other. However, fusing two different DR's requires that the misalignment be no greater than 10% of the minimum wall thickness of the thinner walled pipe. Before you introduce the mirror, you should have all parameters available for this operation. Also check the mirror temperature. Normally, the mirror has a yellow or red lamp, which tells you if the mirror has reached working temperature. To make sure there is no cold air flowing through the pipe, place some plastic bags on each end of the pipe, this will prevent the air from cooling the mirror on one side. You have now shaved the pipe in to a good fit and removed the shaver and introduced the mirror. Push the pipes together against the mirror and raise the pressure to the Bead-up pressure. This pressure needs to be maintained until the Bead-up height has been reached. The bead up height is the height of the bead, which is pres against the mirror. As soon as the Bead up height has been reached, release the pressure down to the Heat Soak pressure. Heat soak pressure is the pressure maintained during the Heat Soak time. As soon as the heat soak time has elapsed, separate the pipes, remove the mirror, and then press together. 8.6-
Fusion the Surface This operation has to be done quite fast, since there is actually a time limit “Transfer time” from the removal of the mirror until the two pipes are pressed together and reached the Fusion pressure. Fusion pressure is the pressure that shall reach during the Transfer time and maintained during the Cooling time. Secure. Clean the inside and outside Of the component (pipe or fitting) ends by wiping with a clean, dry, lint-free cloth or paper towel remove all foreign matter. Align the components with the machine, place them in the clamps and then close the clamps. Do not force pipes into alignment against open fusion machine clamps. (When working with coiled pipe, f possible "S" the pipes on each side of the machine to compensate for coil curvature and make it easier to .) Component ends should protrude past the clamps enough so that facing will be complete. Bring the ends together and check high-low alignment, Adjust alignment as necessary by tightening the high side down.
MS HDPE Pipe Work
PROJ.5180 DE.P10.950.R0
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METHOD STATEMENT for HPDE
Face. Place the facing tool between the components ends, and face them to establish smooth, clean, parallel mating surfaces. Complete facing produces continuous circumferential shavings from both ends. Face until there is a minimal distance between the fixed and moveable clamps. Some machines have facing stops. If stops are present, face down to the stops. Remove the facing tool and clear all shavings and pipe chips from the component ends. Do not touch the component ends with your hands after facing. Align. Bring the component ends together, check alignment and check for slippage against fusion pressure. Look for complete all around both ends with no detectable gaps, and outside diameters in high-low alignment (except for the misalignment permitted in section 6.1). If necessary, adjust the high side by tightening the high side clamp. Do not loosen the low side clamp because components may slip during fusion. Re-face if high low alignment is adjusted. Melt. that the heating tool is maintaining the correct temperature. Place the heating tool between the component ends, and move the ends against the heating tool. The initial should be under moderate pressure (known as pressure) to ensure full . Hold pressure briefly then lower to drag pressure without breaking . pressure must be relieved at the first indication of melt completely around the pipe ends. Procedures for releasing the pressure in the hydraulic cylinder that creates interfacial pressure vary by manufacturer. Review the equipment manufacturers recommended procedure to ensure that only drag pressure is applied during the soak cycle. Hold the ends against the heating tool using only drag pressure. Beads of melted polyethylene will form against the heating tool at the component ends. When the proper melt bead Size is formed (see Table 1), quickly separate the ends and remove the heating tool. During heating, the melt bead will expand out flush to the heating tool surface, or may cud slightly away from the surface. If the melt bead curls significantly away from the heating tool surface, unacceptable pressure during heating may be indicated. Table 1 — Melt Bead Sizes for Corresponding Pipe Sizes Approximate Melt Bead Size (Measure from the heater plate)
MS HDPE Pipe Work
Pipe Size
PROJ.5180 DE.P10.950.R0
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METHOD STATEMENT for HPDE
1/32” – 1/16” (1 – 2mm) About 1/16" (2mm) 1/8" – 3/16” (3 – 5mm) 3/16” – ¼” (5 – 6mm) ¼” – 7/16” (6 – 11mm) About 7/16” About 9/16” About 9/16”
1-1/4" and smaller (40 mm and smaller) Above 1-1/4" throu h 3" above 40 mm throu h 90mm Above 3" throu h B" above 90 mm throu h 225 mm Above g" throu h 12" above 225 mm throu h 315 mm Above 12" through 24" (above 315 mm through 630 mm) Above 24" throu h 36" above 630 mm throu h 915 mm Above 26" throu h 54" above g 15 mm throu h 1300 mm Above 54"
. Immediately after heating tool removal. QUICKLY inspect the melted ends, which should be flat, smooth, and completely melted. If the melt surfaces are acceptable. Immediately and in a continuous motion, bring the ends together and apply the correct ing pressure. Do not slam. Where the equipment permits, 'ramping up' to the ing pressure is desirable. Apply enough ing pressure to roll both melt beads over to the pipe surface A concave melt surface is unacceptable; it indicates pressure during heating. Do not continue. Allow the component ends to cool and start over again. The Correct ing pressure will form a double bead that is rolled over to the surface on both ends.
8.7-
Holding. Cooling time is the time in which the pipe has to be left undisturbed. Under no circumstances shall the clamps be opened or the pressure released until the cooling time has elapsed. Hold ing pressure against the ends until the t is cool. The t is cool enough for GENTLE handling when the double bead is cool to the touch. Cool for about 30 — 90 seconds per inch of pipe diameter. Do not try to shorten cooling time by applying water, wet clothes or the like. Avoid pulling, installation, pressure testing and rough handling for at least an additional 30 minutes. Heavier wall thickness pipes require longer cooling times. Inspect. On both sides, the double bead should be rolled over to the surface, and be uniformly rounded and consistent in size all around the t. As illustrated in Figure 3, the double bead width should be 2 to 2-1/2 times its height above the surface, and the v-groove depth between the beads should not be more than half the bead height. When butt fusing to molded fittings, the fittings side bead may have an irregular appearance, this is acceptable provided the pipe side bead is correct.
MS HDPE Pipe Work
PROJ.5180 DE.P10.950.R0
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METHOD STATEMENT for HPDE
It is not necessary for the internal bead to roll over to the inside surface of the pipe. When butt fusing pipe of dissimilar polyethylene materials, melt bead size may vary due to differences in melt index. This is acceptable provided the melt bead size is sufficient. The fusion t must be kept under fusion pressure until t has sufficiently cooled. Maintain fusion pressure against the piping component ends for a minimum of 11 minutes per inch (25.4mm) of pipe wall. Avoid high stress such as pulling, installation or rough handling for an additional 30 minutes or more after removal from the fusion machine
9- INSPECTION 9.1-
Welding Checks The double bead should be rolled over onto the adjacent surfaces, and be uniformly rounded and consistent in size all around the t. As illustrated in the Figure below, all beads will not necessarily have equal size. The cleavage between the beads must not be lower than the wall of the pipe as shown in the lower right illustration. When butt fusing pipe to molded fittings, the fitting side bead may have an irregular appearance. This is acceptable provided the pipe side bead is correct. It is not necessary for the internal bead to roll over to the inside surface of the pipe. When butt fusion pipe of dissimilar polyethylene materials, melt bead size may vary due to differences in melt index. This is acceptable provided the melt bead size is sufficient. The mirror-welding machine, if coupled to a data log, will give a printout confirming the parameters used during welding of a specific seam and approval/rejection of the welded seam.
9.2-
Defects & Causes BUTT FUSION TROUBLESHOOT DEFECTS CAUSES Excessive double bead width Overheating Excessive ing force Double bead v-groove too deep Excessive ing force Insufficient heating Pressure during heating Flat top on bead Excessive ing force Overheating Non-uniform bead size around pipe Misalignment Defective heating tool Worn equipment Incomplete facing
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PROJ.5180 DE.P10.950.R0
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METHOD STATEMENT for HPDE
One bead larger than the other
Beads too small Bead not rolled over to surface
Beads too large Square type outer bead edge Rough, Sandpaper like, bubbly or pockmarked melt bead surface
9.3-
Misalignment Component slipped in clamp Worn equipment Heating iron does not move freely in the axial direction Defective heating tool Incomplete facing Also possible when fusing bimodal pipes to uni-modal pipes Insufficient heating Insufficient ing force Shallow v-groove – Insufficient heating & insufficient ing force Deep v-groove – Insufficient heating & excessive ing force Bead on bimodal pipe may have slight gap to the pipe surface Excessive heating time Pressure during heating Hydrocarbon (gasoline vapors, spray paint fumes, etc.) contamination
Rules for Butt Weld Fusion NEVER • Attempt to weld together pipes of different SDR (wall thickness). • Touch trimmed pipe ends. • Leave trimming swarf inside pipe or on welding machine. • Allow equipment to get wet or dusty. • Use non-approved machinery. • Remove a weld from the machine before cooling time has elapsed. • Allow untrained personnel to use welding equipment. • Cut corners in any part of the welding procedure. • Weld pipes of different material on site (In factory controlled conditions it may be possible to do this). • Use a generator of inadequate capacity
9.4-
Report. Fill out the Pre-weld and after Weld Inspection check list and report as attached with ITP for HDPE Butt Weld Fusion. Prepare a log sheet to maintain calibration history of all equipment. Ensure tool box talk is carried out and briefed to all workers special to operators and welders before start the work.
MS HDPE Pipe Work
PROJ.5180 DE.P10.950.R0
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METHOD STATEMENT for HPDE
10- PRESSURE TESTING 10.1- Pressure Testing Outside the Trench: If specified by the engineer, pressure testing may be conducted prior to pipe installation. After the pipe has been ed, fill it with water, carefully bleed off any trapped air. Subject the pipe to a hydrostatic test pressure that is 1.5 times the system design pressure for a maximum of 3 hours. During this time, add water periodically to maintain the test pressure; this compensates for the initial stretching of the pipe. The line pressure tightness is determined by visual observation; therefore, it is not necessary to measure the make-up water. Examine every fused t; any leakage must be repaired and then retested. NOTE: It shall be the responsibility of the contractor to ensure that appropriate safety precautions are observed during hydrostatic testing above ground.
10.2- Pressure Testing Inside the Trench: Fill the pipeline with water after it has been laid; bleed off any trapped air. Subject the lowest element in the system to a test pressure that is 1.5 times the design pressure, and check for any leakage. When, in the opinion of the engineer, local conditions require that the trenches be backfilled immediately after the pipe has been laid, apply the pressure test after backfilling has been completed but not sooner than a time which will allow sufficient curing of any concrete that may have been used. Typical minimum concrete curing times are 36 hours for early strengths and 7 days for normal strengths. The test procedures consist of two steps; the initial expansion and the test phase. When test pressure is applied to a water filled pipe, the pipe expands. During the initial expansion of the pipe under test, sufficient make-up water must be added to the system at hourly intervals for 3 hours to maintain the test pressure. After about 4 hours, initial expansion should be complete and the actual test can start. When the test is to begin, the pipe is full of water and is subjected to a constant test pressure of 1.5 times the system design pressure. The test phase should not exceed 3 hours, after which time any water deficiency must be replaced and measured. Add and measure the amount of make-up water required to return to the test pressure and compare this to the maximum allowance in the table below. An alternate leakage test consists of maintaining the test pressure (described above) over a period of 4 hours and then dropping the pressure by 10 psi (0.69 MPa). If the pressure then remains within 5% of the target value for 1 hour, this indicates there is no leakage in the system.
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METHOD STATEMENT for HPDE
NOTES: Under no circumstances shall the total time under test exceed 8 hours at 1.5 times the system pressure rating. If the test is not complete within this time limit (due to leakage, equipment failure, etc.), the test section shall be permitted to “relax” for 8 hours prior to the next test sequence. Air testing is not recommended. Additional safety precautions may be required. Above procedure taken from PPI Technical Report TR-31 by the Plastic Pipe Institute. If does not meet the engineering project requirement, a new and separate pressure procedure shall be prepared and followed.
MS HDPE Pipe Work
PROJ.5180 DE.P10.950.R0
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