Q.
Explain any three (3) of the following:
a) One pipe system in building sanitation system.
b) The location of manhole in sewerage system.
c) Separate system in underground sewerage system.
d) Factors to be considered in selecting sanitary appliances.
(25 marks, 2018 Q4)
a) One pipe system
In this system of plumbing the waste connections from sinks, baths, wash basins and the soil pipe which is connected directly to the drainage system. Gully traps and waste pipes are completely dispensed with. But all the traps of wC.s basins, etc are completely ventilated to preserve the water seal by a separate vent pipe.
The following precautions should be taken in this plumbing system.
a) All the joints off waste pipes should be air-tight.
b) Each waste pipe should be connected to common stack directly.
c) Vent pipe diameter should not be less than 50 mm.
d) The waste pipe should join the stack, above the soil branch at each floor.
e) All traps should be provided with a deep water seal of not less than 7.5cm.
Ref:
http://www.dailycivil.com/system-of-plumbing-in-building-2/
b) manhole
Manhole, diversion manhole, what is it?
Manhole location.
Manhole is provided when
- There is change in grade of sewer
- There is change in alignment
- There is change in size of sewer
- At junction of two or more sewers
- Manhole is also provided in straight alignment of sewers at regular intervals depending upon the diameters of sewers.
Similar question was ask in 2015 Q7(d).
c) separate underground sewerage
d) selecting sanitary appliances
Ref:
Earlier post.