SANITARY PIPING SYSTEM
TWO PIPES SYSTEM The most expensive of the soil and waste disposal system Only be used in circumstances Need to connect the appliances to the a separate waste stack Waste stack connected to the horizontal drain either via a rest bend or a back inlet gully Waste appliances are connected such as basin, sink, bidets, and showers connected to a waste stack and soil appliances as WCS are connected to the soil stack.
One Pipes system Two Pipes System
ONE PIPE SYSTEM The one-pipe system was an early attempt to economies in the labour and materials. Less in amount of of pipes work and cheaper to install Although this was a big advantage economically, it was not accepted by all local authorities for many years. Used successfully for multi-story buildings such as blocks of flats It is recommended that discharge pipes are fitted inside the building for refurbishment work.
Figure of one pipe system
One-pipe system (note: this is almost identical in design to the modern fully ventilated system). With this system both soil and waste discharges are connected to a common discharge pipe. All traps subject to risk of siphonage are fully ventilated
Soil and waste water are separated above ground l evel but discharge into same underground drainage system.
THE DRAINAGE SYSTEM
SOLID WASTE OR REFUSE DISPOSAL
The combined system The foul water from sanitary appliances and the r ainwater from roofs and other surfaces are carried by single drain to a combined sewer. The cost required is low, but the load on the sewerage works is high.
Solid Waste = unwanted solid material that need to be disposed hygienically without affect to the environment. environment.
Solid waste Domestic o E.g: Food, Bottles, Cans, Rags and Carpets, Furniture Commercial o E.g: Domestic, Papers & Stationery Industrial o E.g: Toxic, Offensive, Dangerous
The Separate System The foul water from the sanitary appliances is carried by a foul water drain to afoul water sewer and the rain water from the roofs and the other surfaces is carried by a surface water drain into a surface water sewer The system is more expensive but the load on the sewage works is greatly reduce.
Partially separate system In the partially separate system, most of the rainwater is carried by the surface water drain into the surface water sewer. In order to save cost however, an isolated rainwater inlet is connected to the foul water drain.
Collection System Refuse Bin Refuse Chutes Garchey System Sink Grinders Technocuum System Centralsuy system
Drainage System 1. Rain water and our waste water 2. Convey to small drain 3. Continue to big drain 4. Junction of big drain 5. Continuously to water treatment plant
Refuse Bin This is for non-high rise flats. Refuse gathered into disposable plastic bags & placed inside bins to be collected. •
Refuse Chutes i) Refuse chute + refuse containerii) Refuse chute + incinerator – lorries Refuse chute is a hollow shaft, built-in the high rise flat of circular, square or rectangular shaped. At the top is ventilation vent, every floor is inlet hopper & at the bottom is refuse container for type i) & incinerator for type ii) The number and sitting or refuse chutes depend upon 1. The layout of building 2. The type of storage and collection 3. Volume of refuse 4. Access for refuse vehicle The chute should be sited away from the habitable rooms and not more than 30 m, measured horizontally, from each dwelling It is cheaper to provide space for additional storage beneath the chutes The internal surface of the chute must be smooth and impervious to moisture. It should be constructed of refactory material that will provide at least one hour fire resistance. The refuse chamber should also be of refactory material that will provide at least one hour fire resistance resistance •
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Garchey system (the Mathew-hall garchey system) Consist of special sink unit + stack pipe (waste pipe) + collection chamber + vacuum lorries + sewer In this sytem of refuse disposal foodwaste, bottles, cans and cartons are disposed of at the source without the need to grind or crush the refuse A bowl beneath the sink retains the normal waste water. Refuse is placed inside a central tube in the sink and when the tube is raised the waste water and the refuse are carried away down a stack pipe to a chamber at the base of the building The refuse from the chamber is collected at weekly intervals by a special tanker in which the refuse is compacted into a damp, semi-solid mass that easy to tip. One tanker can collect the refuse from up to 200 dwellings in one load The waste water from the tanker is forced into the foul water sewer •
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Sink Grinders Refuse insert to sink outlet, run water, close plug,’on’ electrical switch, built in electrical motor runs cutting/grinding refuse. Refuse become smaller debris. Refuse flow with water into sewer. Suitable only for small biodegradable waste. •
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LOSS TRAP WATER SEAL 1. Self siphonage Self siphonage is caused by a moving plug of water in the waste pipe causing siphonage of the trap
4. Capillary attraction A piece of rag or string caught on the outlet of the trap will cause the loss of seal by capillary attraction
2. Induced siphonage Induced siphonage siphonage is caused by the discharge from one trap causing siphonage of another trap connected to the same waste pipe
5. Wavering out Gusts of wind blowing across the top of a stack will cause wavering of the water and a loss of trap seal
3. Back pressure or compression Back pressure or compression is cause when the water flowing down a stack changes direction at the bend which compresses the air in the pipe and forces out the trap water seal
RESEALING AND ANTI-SIPHON TRAPS 1. The McAlpine resealing trap The McAlpine trap has a reserve chamber into which the water is forced when siphonage takes place. After siphonage the water in the chamber falls and reseals the trap.
4. The anti-siphon trap The anti-siphon trap has a valve on its outlet which opens and allows air flow into the outlet of the trap thus preventing sophonage
2. The Grevak resealing trap The grevak trap contains an anti siphonage pipe through which air flow to break the siphonic action
Unfortunately resealing and anti-siphon traps require more maintenance than ordinary traps and they are liable to be noisy DISPOSAL METHOD All the waste collected from the collection system either treated or not treated or partially treated must be disposed. •
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3. The Econa resealing trap The econa trap contains a cynlinder on the outlet into which the water flows when the trap is siphoned. After siphonage has taken place the w ater in the cylinder reseals the trap
Method 1. 2. 3. 4.
5. 6.
available : Sea Dumping -unhygienic -unhygienic and environmental risk Open land dumping - unhygienic and environmental risk Controlled landfill - leached Incinerator -opposed only on the ground that they cause pollution and are not environment environment friendly. Recycle Plant -high -high capital but environmental friendly (long term profit) Wastewater treatment plant (for sink unit &sink grinders) - Plant-high capital but environmental environmental friendly (long term profit)
