Drainage Pipeworks Design Flashcards
How does the water flow?
By gravity through a gradient that provides a higher flow velocity than 1 m/s to achieve self cleansing
How should be the pipe routing?
Straight to avoid bend
What is the full-bore flow for vertical and horizontal drain?
25% for vertical and 50% for horizontal. Should be avoided
Venitlation
Provided for every part of the drainage system
Supports
Adequate supports provided to the entire length especially for plastic pipes
Why should have Cleaning eye and where?
For every pipe fitting for easy rodding in case of blockage
Where should Traps be provided? What does it do? What does effectively prevent?
At the outlet of each sanitary fitment. Separates drainage system from interior space. Foul air, flushing noise and insects.
How does a trap work
Water is retained inside the U-section (water seal). Water seal is required to be maintained at 50 mm for waste water systems and 80 mm for soil system.
Self siphonage
Loss of water seal. Only wash basins not baths, sinks, etc. Is defined as the extraction of water from a trap by siphonage set up by the momentum of the discharge from the appliance to which the trap is attached.
Induced siphonage
Caused by the discharge of water from another sanitary fitting connected to the same pipe. Water in branch pipe may draw air from it creating a partial vacuum and causing siphonage
What was the cause of SARS spread?
Loss of water seal
How to prevent loss of water
By ventilation pipe that provides air to compensate the negative pressure
Resealing trap
Trap re seals itself after the siphonage.
Anti siphonage trap
Anti vacuum valve. Whenever the air pressure of the trap is lower than atmosphere, the flap of the device opens and allows air goes into compensate
