GMJ 9189 PHASE 3 cold water MCQ part 2

A pump is required to lift water to a storage cistern at height. A delivery rate of 5kg/s is required and the total length of pipework (including pipe valves and fittings) is 40m. Given a pump efficiency of 75%, what is the required power of the pump in watts?

• 1,765 watts

• 1,962 watts

• 2,609 watts

•   2,995 watts

What should be fitted to the water supply feeding an accumulator to prevent the latter becoming damaged?

• Strainer, check valve and pressure reducing valve

• Strainer, check valve and gauge

• Check valve, pressure relief valve and gauge

• Check valve, water softener and regulating valve

If the mains pressure to an accumulator is 3 bar, then what would be the most suitable air charge pressure within the vessel?

• 3 bar

• 2.5 bar

• 1.5 bar

• 0.5 bar

An accumulator has a storage volume of 180 litres. If it feeds a bath tap with a flow rate of 11 litres per minute, how long will the accumulator assist in increasing the pressure before it starts to replenish?

• 11 mins

• 16 mins

• 18 mins

• 22 mins

A boosted cold water system is fitted with a break cistern at low level and a storage cistern at high level. The pump seems to have seized after ‘running dry’ for some time. What control component within the system is most likely to have failed and allowed this to happen?

• Float operated valve within the storage cistern

• Float operated level shut-off switch within the storage cistern

• Float operated valve within the break cistern

• Float operated low level shut-off switch within the break cistern

What piece of test equipment is most suitable to check the run current of a boost cold water pump during maintenance or fault-finding activities?

• Voltmeter

• Multi-meter

• Low resistance Ohmmeter

• Clip-on Ammeter

A CWSC is overflowing during off-peak periods. What is the most likely cause?

• Blocked distribution pipe outlet

• Faulty level switch

• Split washer within FOV

• Pressure reducing valve set too high

How often should a CWSC be checked for contamination and general condition within an apartment block?

• Monthly

• Quarterly

• Half yearly

• Annually

A sentinel outlet may be described as:

• a tap at the mid-position within a system

• the taps at the furthest and closest locations to the supply

• the taps at the highest and lowest points

• A tap outlet which is operated the least frequently

What activities should be carried out on a boost cold water or shower pump?

• Maintenance activities, as directed by manufacturers’ guidelines

• None – most pumps are hermetically sealed and do not require nay maintenance

• Pump seals replaced and drive shafts lubricated annually

• Impeller cleaned and pump vented half yearly