Drainage power point 5 2025

What is a common reason for trap seal loss in warmer climates and holiday properties?

• Freezing

• Evaporation

• Corrosion

• Blockage

What causes 'wavering out' in a trap seal?

• High water pressure

• Wind passing over the top of a soil stack

• Blocked pipes

• Excessive use of appliances

What can assist with the problem of trap seal loss due to wavering out?

• A wind cowl

• Increasing water flow

• Using chemical cleaners

• Reducing appliance use

What does the loss of water depth in the trap seal result from?

• Pressure fluctuation

• High temperature

• Chemical reaction

• Blockage

What is 'trap seal loss' due to momentum?

• When a small amount of water is slowly discharged down a trap

• When a large amount of water is suddenly discharged down a trap, carrying the trap seal out

• When air pressure increases in the trap

• When the trap is blocked by debris

What happens when water is poured at high speed directly above the outlet of a trap?

• The water remains in the trap

• The momentum of water carries away the water seal

• The trap fills with air

• The outlet gets blocked

What is capillary action in the context of trap seal loss?

• Capillary action generally happens in S traps when long fibres or hairs get caught over the top of the weir. Capillary action then draws the trap seal water up and over the weir.

• Capillary action is the process where air pressure forces water out of the trap seal.

• Capillary action occurs when the trap seal evaporates due to high temperatures.

• Capillary action is when the trap seal is lost due to a sudden increase in water flow.

Where does capillary action generally happen in plumbing traps?

• P traps

• S traps

• U traps

• Bottle traps

What is self-siphonage?

• When a single appliance discharges and pulls its own trap out

• When multiple appliances discharge at the same time

• When water is added to the trap

• When the waste pipe is blocked

What is the easiest way to overcome the problem of self-siphonage in basins?

• Increase the waste pipe diameter

• Use an anti-vac trap

• Reduce water usage

• Make the waste pipe steeper