Below-Ground Drainage (Leaving Cert Construction Studies): Flashcards
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Practise the cards
10 cards from this deck
What is siphonage in drainage?
What is siphonage in drainage?
Pressure differences creating suction that empties water traps, allowing sewer gases to enter buildings
Cause of self-siphonage
Cause of self-siphonage
Waste pipe runs completely full, reduces pressure, creates suction that pulls water from trap
Cause of induced siphonage
Cause of induced siphonage
Water flowing down stack creates suction in connected waste pipe
What is back pressure in drainage?
What is back pressure in drainage?
Pressure buildup where stack changes direction at bottom
Modern underground drainage material
Modern underground drainage material
uPVC (unplasticised polyvinyl chloride)
When are manholes used (depth criterion)?
When are manholes used (depth criterion)?
When drain depth exceeds 1 metre
Where are inspection chambers located?
Where are inspection chambers located?
Drain heads, level changes, direction changes, new connections
Typical minimum drainage pipe diameter
Typical minimum drainage pipe diameter
100mm
When to test underground drainage
When to test underground drainage
Before backfilling
Air test pressure maintenance duration
Air test pressure maintenance duration
Three minutes