WBL phase 1 exam

What colour is MDPE pipework?

• Red

• Green

• Blue

• Yellow

What British standard should a screw down stop tap conform to?

• BS1010

• BS2020

• BS3030

• BS4040

Where should a drain off valve (DOV) be installed?

• Below the main water line

• Above incoming stop valve and at all low points in system

• Next to the water heater

• At the highest point in the system

What is backflow?

• Water flowing in the correct direction

• Water being allowed to flow back in the wrong direction

• Water flowing faster than normal

• Water being filtered

What backflow prevention device is required when preventing category 3 water from being contaminated by category 2 water?

• Single check valve

• Double check valve

• RPZ valve

• Air gap

Why are BS1212 ball valves now not allowed to be fitted?

• They are too expensive.

• Air gap is not adequate. Can cause backflow issues.

• They are too large for standard fittings.

• They are made of non-durable materials.

Is a rigid silencer okay to use on a BS1212 part 3 ball valve?

• Yes

• No

• Only if approved by a supervisor

• Sometimes

What is water hammer?

• A tool used for plumbing

• Banging noise made from water pipes

• A type of valve

• A method of water purification

What is “ball murmur” and how can it be overcome?

• A type of valve malfunction; replace the valve

• A type of water hammer caused by float operated valve opening and closing quickly; install BS1212 part 4 equilibrium float valve to prevent

• A noise from the boiler; increase the water temperature

• A type of leak; seal the pipe

Would lowering the ball on a BS1212 part 2 float valve arm increase or decrease the amount of water in a cistern?

• Increase

• Decrease

• No change

• It depends on the water pressure