Basic Principles Of Sanitation 37204e
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Basic Principles of Sanitation Some of the ideal principles of sanitations are Supply of Water Treatment of Waste Collection and conveyance Prevention of dampness Orientation of Building Space planning (Interior Space arrangement)
SANITARY WASTE & SEWERAGE SYSTEM
WASTE & SEWERAGE SYSTEM Sullage:SANITARY Sullage (greywater): commonly understood to refer to domestic wastewater from showers, laundry use and cooking, but does not include sewage. Sewage: The term sewage is used to indicate the liquid waste from the community and it includes sullage, discharge from latrines, urinals, etc industrial waste and storm water. Sewer: The underground conduits or drains through which it is conveyed are known as the sewers. Sewerage: The entire science of collecting and carrying sewage by water carriage system through sewers is known as sewerage. Garbage: The term indicates dry refuse which includes decayed fruits, grass, leaves, paper pieces, sweepings, vegetables etc. Refuse: The term refuse is used to indicate all kinds of dry wastes of the community (i.e.,) street and house sweepings, garbage etc. CLASSIFICATION OF SEWAGE: 1. Storm Sewage: Which includes surface runoff developed during and immediately after rainfall over the concerned area. 2. Sanitary Sewage: Which includes the liquid wastes of domestic and industrial places. This sewage is extremely foul in nature and required to be disposed of very carefully.
SANITARY WASTE & SEWERAGE SYSTEMS OF SEWERAGE METHODS:
SYSTEM
1. Conservancy System: In this system various types of refuse and storm water are collected, conveyed and disposed off separately by different methods in this system. This method is also called dry system and is in practice from very ancient times. This method is adopted in small towns, villages and undeveloped portions of large city even though it is out of date system. In this method garbage or dry refuse is collected from the dustbins and conveyed by trucks or covered carts once or twice in a day. All the uncombustible portions such as sand, dust, clay, ashes etc are used for filling low lying areas and combustible portions such as dry leaves, waste paper, broken furniture etc… are burnt. The decaying fruits, vegetables, grass are first dried and then disposed of by burning or in the manufacture of manure. Human excreta or night soil is collected in separate liquid and semi-liquid wastes by animal drawn carts, trucks or tractor trailors and buried in trenches. After 2-3 years the buried night soil is converted into an excellent manure which can be used for growing crops. In this system sullage and storm water are also carried separately in closed or open drains upto the point of disposal, where they are allowed to mix up with streams, rivers or sea.
SANITARY WASTE & SEWERAGE SYSTEM
2. WATER CARRIAGE SYSTEM: In this system, the excremental matters are mixed up in the large quantity of water and are taken out from the city through properly designed sewerage systems where they are disposed off after necessary treatment in a satisfactory manner. The sewage so formed in water carriage system consists of 99.9 percentage of water and 0.1 percentage of solid matters. All the solid matters remain in suspension in the sewage and do not change the specific gravity of water. So all the hydraulic formulae can be directly used in the design of sewerage system and treatment plants.
GENERAL LAYOUT OF SANITARY FITTINGS TO HOUSE DRAINAGE ARRANGEMENTS The following should be kept in mind in planning the layout of drainage connections to the various fittings. 1. The layout should be simple and direct (both horizontal and vertical). 2. Horizontal pipes should lay at designed slope. 3. Concrete pads should be provided to the pipes laid on earthfill.
4. Long or short sweep quarter bends or two 45° or eight bends for making 90° turn should be provided. 5. Only sanitary tees and quarter bends are used for a change of pipe from horizontal to vertical 6. Manholes should be provided at all points of intersections and change of direction of pipes 7. All soil pipes, waste pipes and ventilating pipes may be grouped in shafts or ducts for easy inspection and maintenance. 8. A clear minimum distance of 5cm should be maintained from walls to all surface pipes.
9. The waste pipes should be separated from house drain by means of gully traps to prevents entry of foul gases, vermin etc into the building. 10. Traps are required for every sanitary fixture and they should be as close to the fixture as possible.
The typical layout of single storeyed building drainage system is shown in the fig Plan of the Layout Drainage in Single Storeyed Building
In the case of multistoried building , sanitary blocks are arranged one above the other on different floors. This facilitates
the same soil pipe or waste pipe or vent pipe to serve the various fixtures in different floors. Inspection chamber is provided at the ground where the solid pipe s the house drain
A vent pipe or anti syphonage pipe is also provided to preserve the waste seals of sanitary fittings. The soil pipes and vent pipes are provided with wire cage at the top to
avoid the birds making nests in the pipe fig shows the drainage system of multi storeyed buildings.The drainage system in the building is as per IS1172-1971 and IS1742- 1972.
Layout of Drainage System in Multistoreyed
Drainage system in multi storied building In the drainage system for a multi-storey building, the drains from the plumbing fixtures are connected to vertical drain stacks that convey the waste and sewage to below the lowest floor of the building. The fixture drain traps must be vented The fixture vent pipes must extend through the roof to outdoors. They can be run individually or be combined into one or more vents through the roof. Wherever possible, the sanitary drainage system from a building should discharge to the public sewer by gravity. All plumbing fixtures located below ground level should be pumped into the public sewer or the drainage system leading to the sewer. The pump line should be as short as possible and looped up to a point not less than 0.6 metres (24 inches) above ground level to prevent backsiphonage of sewage. The pump discharge rate should be controlled The sump pits for sewage pumps must have sealed covers, be vented to outdoors and have automatic level controls and alarms. Sewage pumps in multiple dwellings and in multi-storey dwellings should be duplex, with each pump having 100% of the required pumping capacity for the building. Alternatively, an approved vacuum drainage system may be considered.
Vacuum drainage systems In a vacuum drainage system, the differential pressure between the atmosphere and the vacuum becomes the driving force that propels the wastewater towards the vacuum station. Vacuum drainage systems should be considered when one or more of the following conditions exist:
• water shortage; • limited sewerage capacity; • where separation of black water and greywater is desired; • where drainage by gravity becomes impractical;
• where a high water table exists; • in hospitals, hotels, office buildings or other areas where congested usage occurs, and flexibility in pipe routing is required to drain appliances; • restricted construction conditions;
• building refurbishment
The following technical are used in the house drainage 1. Anti-siphonage pipe – The pipe used in the house drainage to preserve the water seal of traps is known as the antisiphonage. 2. Cowl - The top of vent pipe provided with slits or narrow openings to escape. 3. fresh inlet – The last manhole which connects the house drain with the public sewer is provided with an inlet of fresh air to dilutes the sewage gases. 4. Soil pipe – The pipe which carries discharges from soil fittings such as urinals, water closets etc. 5. Ventpipe – The pipe installed for the purpose of ventlation is known as ventpipe through which foul gases escape into atmosphere. 6. Waste pipe – The pipe which carries discharges from sanitary fittings such as bathrooms, kitchens, sinks etc. SANITARY FITTINGS: The sanitary fittings are required in house drainage for the efficient collection and removal of waste water from the house to house drain. The following are some of the sanitary fittings. 1. Traps. 2. Water closets. 3. Flushing cisterns.
4. Urinals. 5. Inspection chambers. 6. Wash basins. 7. Sinks. 8. Bath tubs etc. TRAPS A trap is a depressed or bent sanitary fitting which always remains full of water (water seal). The function of a trap is to prevent the entry of bad smelling gases into the house. The effectiveness depends upon the depth of water seal, which varies from 25 to 75mm TYPES OF TRAPS: 1. Classification according to shape as shown in fig a. P-trap.
b. Q-trap. c. S-trap.
2. Classification according to use as shown in fig
Floor trap ,Gully trap & Intercepting trap a. Floor trap – made of cast iron and placed in bathrooms, kitchens, sinks etc. b. Gully trap - made of stone wave and C.I. grating is provided. It is placed near the external face of wall and kept slightly higher level than ground level.
c. Intercepting trap – This trap has water seal of about 100mm and provided in the last manhole of house drainage system. It thus conveys sewage from house to the public sewer. WATER CLOSETS: The water closets are of following two types 1. Indian type water closet 2. European type water closet
INDIAN TYPE WATER
EUROPEAN TYPE WATER CLOSET
FLUSHING CISTERNS: In order to flush the water closets and urinals the arrangement made is called flushing cistern. These are made of cast-iron or porcelain with a capacity of 5 to 15 litres. It consists of a bell connected to flushing chain through a lever. When the chain is pulled, the bell is lifted up and the water in the tank rushes through the flushing pipe by syphonic action. The float valve now allows the water from the inlet into the cistern and thus the cistern is ready for next flushing. The details are as shown in the fig .
MANHOLES Manholes are provided at every change of alignment, gradient or diameter of the sewer. Manholes are provided for inspection, cleaning, repairs and maintenance of the sewer. A Manhole consists of a) Working chamber. b) An access shaft and c) A strong cover on the top flush with the road level. SEPTIC TANK: In order to provide satisfactory disposal of sewage received or obtained from isolated buildings, small institutions, big hotels, camps etc or undeveloped areas of the locality where municipal sewers are not laid, the septic tanks may be adopted. The septic tank is just like a plain sedimentation tank but in septic tank, biochemical reactions by anaerobic bacteria take place as in the case of sludge digestion tanks. During the detention period, the sewage is purified and the effluent is taken to soak pits for disposal. The septic tank is provided with cover at top for avoiding the bad smells occur during the digestion period of sludge.
Caulking Compound
A soft, plastic material consisting of pigment and vehicle, used for sealing ts in buildings and other structures where normal structural movement may occur. Caulking compound retains its plasticity for an extended period after application. It is available in forms suitable for application by gun and knife and in extruded preformed shapes Caulking compounds come in several forms including: • disposable cartridges that fit in caulking guns • pressurized caulking cartridges that need no caulk guns • aerosol cans • squeeze tubes • peel and stick • filler materials (rope caulk, backer rod) Caulking is intended to fill cracks less than 1/4” or 3/8” wide and must adhere to its material to work properly. Different compounds vary in how well they adhere to different materials and in their resilience, durability, flexibility, cost, ease of use and clean up, color, or ability to be painted. When caulking two different materials, choose a compound that will remain flexible.
Caulking compounds are either water-based or solvent-based. Clean up water-based caulking compounds with water before they cure. Clean up solvent-based compounds with solvents and ventilate well.
Typical caulking compounds include • latex, acrylic latex • oil or resin-based • urethane or polyurethane • silicone – household or construction • polyurethane expandable spray foam • water-based low expansion spray foam • butyl rubber • backer-rod • closed-cell foam or rope caulk
INSPECTION CHAMBERS: Inspection chamber is a masonary chamber similar to manhole to provide access for the cleaning, inspection and repair of the drain. This chamber is provided with C.I. cover. The size of this chamber depends on the depth and number of branch connections. The size may be about 60 x 75cm and 90cm deep. They should be constructed at all junctions, bends and at about 10m interval on straight runs of the drains. ANTI-SYPHONAGE PIPE: These pipes are provided to prevent syphonage action and consequent sucking of water seals. Particularly if several lavatory blocks are situated on different storeys discharging in the same soil pipe or waste pipe, the anti syphonage pipe has to be necessarily provided. Because, the flushing in upper floors creates partial vaccum in the pipe at lower region, inducing syphonic action and thus the water seals are sucked in the lower floors. Hence antisphonage pipe or vent pipe is connected to all traps, so that when the partial vaccum occurs due to flushing, it may be immediately broken by suction if air from the vent pipe and seals of traps remain infact.
Interception Chamber
Fig. 187 shows an Intercepting Chamber. These should be built in cement, on a concrete bed at least 9 inches thick, and finished on top with a double or single seal cast-iron manhole cover. The concrete foundation having been put in, the disconnecting trap is placed in position and set perfectly level. There are many varieties of intercepting traps in the market, but a satisfactory one should have a 3-inch weir action and 1 1/2-inch water seal and sweeping arm. The channel pipes (either 1/2 or 3/4 section) and the various branches discharging over them are next fixed and benched round with concrete. A course of brick on edge should be placed on top of the straight half-channel, and the concrete sloped off to the edge of the channel thus formed. This will form a deep channel, which will prevent the excreta from being washed up on to the slopes out of the reach of the next discharge. The sides and slopes of the chamber should then be finished to a smooth surface in cement mortar, 1 to 1.
All half-channel pipes and bends should have 1-inch fall in their length in addition to the general gradient, to compensate for the loss of head due to friction. Should the sewer be at a great depth, ramps may be used to save the expense of laying deep drains. These have a short arm with stopper fixed in same carried through the wall of manhole for rodding the drains. Another form of ramp is that shown by dotted lines, the main pipe being continued full bore direct into the chamber, and a galvanised cast-iron flap valve fixed at the chamber end, to enable the sewage to flow into the chamber should the ramp become blocked. The minimum internal dimensions of chambers should be 3 feet 0 inches by 2 feet 3 inches. In deep drains, however, they may be as large as 4 feet 1 1/2 inch by 2 feet 7 1/2 inches, and be gathered over at a height of 5 feet 6 inches above invert of drain, and continued to ground level with a shaft 1 foot 10 1/2 inches by 1 foot 10 1/2 inches inside dimensions. Chambers over 4 feet deep should have step irons 1 foot 6 inches apart. Where the distance between two inspection chambers exceeds 100 feet, sweeping eyes may be constructed, as shown by Fig. 188. These should be finished with a stopper bedded in soft soap and covered by a slab of York stone and a small hinged cast-iron cover. Inspection chambers are similar in construction to intercepting chambers, but the fresh-air inlet and intercepter are omitted.
PLUMBING SYSTEMS: There are three system of plumbing systems SINGLE STACK: In this system, the waste water from bathroom, kitchen, wash basin, urinals etc and human excreta from water closet is discharged through a singh soil pipe and also this pipe acts as ventilating pipe. The traps should have waterseals at all times at least to a depth of 75mm. ONE PIPE SYSTEM: This is same as single stack system but in addition to this there is a separate vent pipe connected to the fittings and the water seals are protected. This is costlier than single stack system. TWO PIPE SYSTEM: In this system, the soil pipe is connected to all water closets and urinals and the other waste pipe is connected to bath, kitchen and wash basins etc. Both soil pipe and vent pipes are separately ventilated by vent pipes. This system provides very effective and trouble free drainage. But this is costly system.
Pipe Gradients
Above ground and below ground horizontal drainage pipes should be laid to an adequate gradient.
Gradients from 1 in 40 to 1 in 110 will normally give adequate flow velocities.
A gradient of 1 in 80 is suitable for commencing calculations for pipe schemes.
If a gradient is too steep i.e. steeper than 1 in 40, the liquid may run faster than the solids in the sloping foul water pipe thus leaving the solids stranded, which could then block the pipe.
If the gradient is not steep enough, i.e. less than 1 in 110, then the pipe could still block if the solids slow down and become stranded.
The fall in a pipe may be defined as the vertical amount by which the pipe drops over a distance. The distance can be between sections of pipe or between manholes. The diagram below show pipe fall and distance.
A gradient may be defined as fall divided by distance. GRADIENT = FALL / DISTANCE For example is a 24 metre section of drainage pipe has a fall of 0.30 metres, calculate the gradient. Gradient =
0.30 / 24
Gradient = 0.0125 This can be converted into a gradient written as a ratio or 1: some number. Gradient
=
1 / 0.0125 =
80
Gradient = 1 in 80 The above formula may be rearranged for Fall if the gradient is known: FALL
=
GRADIENT X
DISTANCE
For example, calculate the fall in a 50 metre section of foul water pipework if the gradient is to be 1 in 80.
A gradient of 1 in 80 is converted to a number instead of a ratio.
1 / 80 = 0.0125
Fall
=
Gradient x Distance
Fall
=
0.0125 x 50
Fall
=
0.625 metres or 625mm.
The previous diagram may be completed by adding a pipe gradient.
SANITARY WASTE & SEWERAGE SYSTEM
WASTE & SEWERAGE SYSTEM Sullage:SANITARY Sullage (greywater): commonly understood to refer to domestic wastewater from showers, laundry use and cooking, but does not include sewage. Sewage: The term sewage is used to indicate the liquid waste from the community and it includes sullage, discharge from latrines, urinals, etc industrial waste and storm water. Sewer: The underground conduits or drains through which it is conveyed are known as the sewers. Sewerage: The entire science of collecting and carrying sewage by water carriage system through sewers is known as sewerage. Garbage: The term indicates dry refuse which includes decayed fruits, grass, leaves, paper pieces, sweepings, vegetables etc. Refuse: The term refuse is used to indicate all kinds of dry wastes of the community (i.e.,) street and house sweepings, garbage etc. CLASSIFICATION OF SEWAGE: 1. Storm Sewage: Which includes surface runoff developed during and immediately after rainfall over the concerned area. 2. Sanitary Sewage: Which includes the liquid wastes of domestic and industrial places. This sewage is extremely foul in nature and required to be disposed of very carefully.
SANITARY WASTE & SEWERAGE SYSTEMS OF SEWERAGE METHODS:
SYSTEM
1. Conservancy System: In this system various types of refuse and storm water are collected, conveyed and disposed off separately by different methods in this system. This method is also called dry system and is in practice from very ancient times. This method is adopted in small towns, villages and undeveloped portions of large city even though it is out of date system. In this method garbage or dry refuse is collected from the dustbins and conveyed by trucks or covered carts once or twice in a day. All the uncombustible portions such as sand, dust, clay, ashes etc are used for filling low lying areas and combustible portions such as dry leaves, waste paper, broken furniture etc… are burnt. The decaying fruits, vegetables, grass are first dried and then disposed of by burning or in the manufacture of manure. Human excreta or night soil is collected in separate liquid and semi-liquid wastes by animal drawn carts, trucks or tractor trailors and buried in trenches. After 2-3 years the buried night soil is converted into an excellent manure which can be used for growing crops. In this system sullage and storm water are also carried separately in closed or open drains upto the point of disposal, where they are allowed to mix up with streams, rivers or sea.
SANITARY WASTE & SEWERAGE SYSTEM
2. WATER CARRIAGE SYSTEM: In this system, the excremental matters are mixed up in the large quantity of water and are taken out from the city through properly designed sewerage systems where they are disposed off after necessary treatment in a satisfactory manner. The sewage so formed in water carriage system consists of 99.9 percentage of water and 0.1 percentage of solid matters. All the solid matters remain in suspension in the sewage and do not change the specific gravity of water. So all the hydraulic formulae can be directly used in the design of sewerage system and treatment plants.
GENERAL LAYOUT OF SANITARY FITTINGS TO HOUSE DRAINAGE ARRANGEMENTS The following should be kept in mind in planning the layout of drainage connections to the various fittings. 1. The layout should be simple and direct (both horizontal and vertical). 2. Horizontal pipes should lay at designed slope. 3. Concrete pads should be provided to the pipes laid on earthfill.
4. Long or short sweep quarter bends or two 45° or eight bends for making 90° turn should be provided. 5. Only sanitary tees and quarter bends are used for a change of pipe from horizontal to vertical 6. Manholes should be provided at all points of intersections and change of direction of pipes 7. All soil pipes, waste pipes and ventilating pipes may be grouped in shafts or ducts for easy inspection and maintenance. 8. A clear minimum distance of 5cm should be maintained from walls to all surface pipes.
9. The waste pipes should be separated from house drain by means of gully traps to prevents entry of foul gases, vermin etc into the building. 10. Traps are required for every sanitary fixture and they should be as close to the fixture as possible.
The typical layout of single storeyed building drainage system is shown in the fig Plan of the Layout Drainage in Single Storeyed Building
In the case of multistoried building , sanitary blocks are arranged one above the other on different floors. This facilitates
the same soil pipe or waste pipe or vent pipe to serve the various fixtures in different floors. Inspection chamber is provided at the ground where the solid pipe s the house drain
A vent pipe or anti syphonage pipe is also provided to preserve the waste seals of sanitary fittings. The soil pipes and vent pipes are provided with wire cage at the top to
avoid the birds making nests in the pipe fig shows the drainage system of multi storeyed buildings.The drainage system in the building is as per IS1172-1971 and IS1742- 1972.
Layout of Drainage System in Multistoreyed
Drainage system in multi storied building In the drainage system for a multi-storey building, the drains from the plumbing fixtures are connected to vertical drain stacks that convey the waste and sewage to below the lowest floor of the building. The fixture drain traps must be vented The fixture vent pipes must extend through the roof to outdoors. They can be run individually or be combined into one or more vents through the roof. Wherever possible, the sanitary drainage system from a building should discharge to the public sewer by gravity. All plumbing fixtures located below ground level should be pumped into the public sewer or the drainage system leading to the sewer. The pump line should be as short as possible and looped up to a point not less than 0.6 metres (24 inches) above ground level to prevent backsiphonage of sewage. The pump discharge rate should be controlled The sump pits for sewage pumps must have sealed covers, be vented to outdoors and have automatic level controls and alarms. Sewage pumps in multiple dwellings and in multi-storey dwellings should be duplex, with each pump having 100% of the required pumping capacity for the building. Alternatively, an approved vacuum drainage system may be considered.
Vacuum drainage systems In a vacuum drainage system, the differential pressure between the atmosphere and the vacuum becomes the driving force that propels the wastewater towards the vacuum station. Vacuum drainage systems should be considered when one or more of the following conditions exist:
• water shortage; • limited sewerage capacity; • where separation of black water and greywater is desired; • where drainage by gravity becomes impractical;
• where a high water table exists; • in hospitals, hotels, office buildings or other areas where congested usage occurs, and flexibility in pipe routing is required to drain appliances; • restricted construction conditions;
• building refurbishment
The following technical are used in the house drainage 1. Anti-siphonage pipe – The pipe used in the house drainage to preserve the water seal of traps is known as the antisiphonage. 2. Cowl - The top of vent pipe provided with slits or narrow openings to escape. 3. fresh inlet – The last manhole which connects the house drain with the public sewer is provided with an inlet of fresh air to dilutes the sewage gases. 4. Soil pipe – The pipe which carries discharges from soil fittings such as urinals, water closets etc. 5. Ventpipe – The pipe installed for the purpose of ventlation is known as ventpipe through which foul gases escape into atmosphere. 6. Waste pipe – The pipe which carries discharges from sanitary fittings such as bathrooms, kitchens, sinks etc. SANITARY FITTINGS: The sanitary fittings are required in house drainage for the efficient collection and removal of waste water from the house to house drain. The following are some of the sanitary fittings. 1. Traps. 2. Water closets. 3. Flushing cisterns.
4. Urinals. 5. Inspection chambers. 6. Wash basins. 7. Sinks. 8. Bath tubs etc. TRAPS A trap is a depressed or bent sanitary fitting which always remains full of water (water seal). The function of a trap is to prevent the entry of bad smelling gases into the house. The effectiveness depends upon the depth of water seal, which varies from 25 to 75mm TYPES OF TRAPS: 1. Classification according to shape as shown in fig a. P-trap.
b. Q-trap. c. S-trap.
2. Classification according to use as shown in fig
Floor trap ,Gully trap & Intercepting trap a. Floor trap – made of cast iron and placed in bathrooms, kitchens, sinks etc. b. Gully trap - made of stone wave and C.I. grating is provided. It is placed near the external face of wall and kept slightly higher level than ground level.
c. Intercepting trap – This trap has water seal of about 100mm and provided in the last manhole of house drainage system. It thus conveys sewage from house to the public sewer. WATER CLOSETS: The water closets are of following two types 1. Indian type water closet 2. European type water closet
INDIAN TYPE WATER
EUROPEAN TYPE WATER CLOSET
FLUSHING CISTERNS: In order to flush the water closets and urinals the arrangement made is called flushing cistern. These are made of cast-iron or porcelain with a capacity of 5 to 15 litres. It consists of a bell connected to flushing chain through a lever. When the chain is pulled, the bell is lifted up and the water in the tank rushes through the flushing pipe by syphonic action. The float valve now allows the water from the inlet into the cistern and thus the cistern is ready for next flushing. The details are as shown in the fig .
MANHOLES Manholes are provided at every change of alignment, gradient or diameter of the sewer. Manholes are provided for inspection, cleaning, repairs and maintenance of the sewer. A Manhole consists of a) Working chamber. b) An access shaft and c) A strong cover on the top flush with the road level. SEPTIC TANK: In order to provide satisfactory disposal of sewage received or obtained from isolated buildings, small institutions, big hotels, camps etc or undeveloped areas of the locality where municipal sewers are not laid, the septic tanks may be adopted. The septic tank is just like a plain sedimentation tank but in septic tank, biochemical reactions by anaerobic bacteria take place as in the case of sludge digestion tanks. During the detention period, the sewage is purified and the effluent is taken to soak pits for disposal. The septic tank is provided with cover at top for avoiding the bad smells occur during the digestion period of sludge.
Caulking Compound
A soft, plastic material consisting of pigment and vehicle, used for sealing ts in buildings and other structures where normal structural movement may occur. Caulking compound retains its plasticity for an extended period after application. It is available in forms suitable for application by gun and knife and in extruded preformed shapes Caulking compounds come in several forms including: • disposable cartridges that fit in caulking guns • pressurized caulking cartridges that need no caulk guns • aerosol cans • squeeze tubes • peel and stick • filler materials (rope caulk, backer rod) Caulking is intended to fill cracks less than 1/4” or 3/8” wide and must adhere to its material to work properly. Different compounds vary in how well they adhere to different materials and in their resilience, durability, flexibility, cost, ease of use and clean up, color, or ability to be painted. When caulking two different materials, choose a compound that will remain flexible.
Caulking compounds are either water-based or solvent-based. Clean up water-based caulking compounds with water before they cure. Clean up solvent-based compounds with solvents and ventilate well.
Typical caulking compounds include • latex, acrylic latex • oil or resin-based • urethane or polyurethane • silicone – household or construction • polyurethane expandable spray foam • water-based low expansion spray foam • butyl rubber • backer-rod • closed-cell foam or rope caulk
INSPECTION CHAMBERS: Inspection chamber is a masonary chamber similar to manhole to provide access for the cleaning, inspection and repair of the drain. This chamber is provided with C.I. cover. The size of this chamber depends on the depth and number of branch connections. The size may be about 60 x 75cm and 90cm deep. They should be constructed at all junctions, bends and at about 10m interval on straight runs of the drains. ANTI-SYPHONAGE PIPE: These pipes are provided to prevent syphonage action and consequent sucking of water seals. Particularly if several lavatory blocks are situated on different storeys discharging in the same soil pipe or waste pipe, the anti syphonage pipe has to be necessarily provided. Because, the flushing in upper floors creates partial vaccum in the pipe at lower region, inducing syphonic action and thus the water seals are sucked in the lower floors. Hence antisphonage pipe or vent pipe is connected to all traps, so that when the partial vaccum occurs due to flushing, it may be immediately broken by suction if air from the vent pipe and seals of traps remain infact.
Interception Chamber
Fig. 187 shows an Intercepting Chamber. These should be built in cement, on a concrete bed at least 9 inches thick, and finished on top with a double or single seal cast-iron manhole cover. The concrete foundation having been put in, the disconnecting trap is placed in position and set perfectly level. There are many varieties of intercepting traps in the market, but a satisfactory one should have a 3-inch weir action and 1 1/2-inch water seal and sweeping arm. The channel pipes (either 1/2 or 3/4 section) and the various branches discharging over them are next fixed and benched round with concrete. A course of brick on edge should be placed on top of the straight half-channel, and the concrete sloped off to the edge of the channel thus formed. This will form a deep channel, which will prevent the excreta from being washed up on to the slopes out of the reach of the next discharge. The sides and slopes of the chamber should then be finished to a smooth surface in cement mortar, 1 to 1.
All half-channel pipes and bends should have 1-inch fall in their length in addition to the general gradient, to compensate for the loss of head due to friction. Should the sewer be at a great depth, ramps may be used to save the expense of laying deep drains. These have a short arm with stopper fixed in same carried through the wall of manhole for rodding the drains. Another form of ramp is that shown by dotted lines, the main pipe being continued full bore direct into the chamber, and a galvanised cast-iron flap valve fixed at the chamber end, to enable the sewage to flow into the chamber should the ramp become blocked. The minimum internal dimensions of chambers should be 3 feet 0 inches by 2 feet 3 inches. In deep drains, however, they may be as large as 4 feet 1 1/2 inch by 2 feet 7 1/2 inches, and be gathered over at a height of 5 feet 6 inches above invert of drain, and continued to ground level with a shaft 1 foot 10 1/2 inches by 1 foot 10 1/2 inches inside dimensions. Chambers over 4 feet deep should have step irons 1 foot 6 inches apart. Where the distance between two inspection chambers exceeds 100 feet, sweeping eyes may be constructed, as shown by Fig. 188. These should be finished with a stopper bedded in soft soap and covered by a slab of York stone and a small hinged cast-iron cover. Inspection chambers are similar in construction to intercepting chambers, but the fresh-air inlet and intercepter are omitted.
PLUMBING SYSTEMS: There are three system of plumbing systems SINGLE STACK: In this system, the waste water from bathroom, kitchen, wash basin, urinals etc and human excreta from water closet is discharged through a singh soil pipe and also this pipe acts as ventilating pipe. The traps should have waterseals at all times at least to a depth of 75mm. ONE PIPE SYSTEM: This is same as single stack system but in addition to this there is a separate vent pipe connected to the fittings and the water seals are protected. This is costlier than single stack system. TWO PIPE SYSTEM: In this system, the soil pipe is connected to all water closets and urinals and the other waste pipe is connected to bath, kitchen and wash basins etc. Both soil pipe and vent pipes are separately ventilated by vent pipes. This system provides very effective and trouble free drainage. But this is costly system.
Pipe Gradients
Above ground and below ground horizontal drainage pipes should be laid to an adequate gradient.
Gradients from 1 in 40 to 1 in 110 will normally give adequate flow velocities.
A gradient of 1 in 80 is suitable for commencing calculations for pipe schemes.
If a gradient is too steep i.e. steeper than 1 in 40, the liquid may run faster than the solids in the sloping foul water pipe thus leaving the solids stranded, which could then block the pipe.
If the gradient is not steep enough, i.e. less than 1 in 110, then the pipe could still block if the solids slow down and become stranded.
The fall in a pipe may be defined as the vertical amount by which the pipe drops over a distance. The distance can be between sections of pipe or between manholes. The diagram below show pipe fall and distance.
A gradient may be defined as fall divided by distance. GRADIENT = FALL / DISTANCE For example is a 24 metre section of drainage pipe has a fall of 0.30 metres, calculate the gradient. Gradient =
0.30 / 24
Gradient = 0.0125 This can be converted into a gradient written as a ratio or 1: some number. Gradient
=
1 / 0.0125 =
80
Gradient = 1 in 80 The above formula may be rearranged for Fall if the gradient is known: FALL
=
GRADIENT X
DISTANCE
For example, calculate the fall in a 50 metre section of foul water pipework if the gradient is to be 1 in 80.
A gradient of 1 in 80 is converted to a number instead of a ratio.
1 / 80 = 0.0125
Fall
=
Gradient x Distance
Fall
=
0.0125 x 50
Fall
=
0.625 metres or 625mm.
The previous diagram may be completed by adding a pipe gradient.
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