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Worksheets8202 9189 CJ Cold Water Systems Quiz
Total questions: 20
Worksheet time: 10mins
How can the cold water supply pressure to a property be identified?
By contacting the local council or using a weir gauge at the kitchen sink
By contacting the local council or using a pressure gauge at the supply to the FOV
By contacting the water undertaker or using a pressure gauge at the cistern-fed outlets
By contacting the water undertaker or using a pressure gauge at the kitchen sink
Which formula can be used to determine flow rates through a pipe?
Q = Av
Q = A÷v
Q = m/s
Q = V²
What term is given to the length of pipe when all fittings and components are considered during pipe sizing?
Equivalent length
Actual length
Mean length
Velocity length
Which of the following is not a source of information that should be consulted to assist in pipe sizing for cold water systems?
BS EN 806 -2: 2012
BS EN 806-3: 2012
BS 8558: 2015
BS 4213: 2004
According to guidance, all pipes and joints of a cold water system should be designed for a service life of:
25 years at a temperature of 20°C and a design pressure of 15 bar
50 years at a temperature of 20°C and a design pressure of 10 bar
25 years at a temperature of 25°C and a design pressure of 10 bar
50 years at a temperature of 25°C and a design pressure of 5 bar
What is the recommended storage capacity of a CWSC supplying cold and hot water to a house?
100 litres minimum
150 litres minimum
230 litres minimum
350 litres minimum
What is the recommended flow velocity of cold water within pipework?
Between 0.25m/s and 1.5m/s
Between 0.5m/s and 2m/s
As close as practically possible to 2.5m/s
As close as practically possible to 3.5m/s
Which of the following factors would not directly affect the pressure and flow rates of pipework?
Pipe diameter
Pipe material
Number of bends
pH level of the water supply
Which passage best describes the factors relating to the term ‘Loading Units’?
Material of pipework, type and number of outlets
Type of outlets, size of outlets and distance from the supply
Flow rate, length of time in use and frequency of use of outlets
Length of pipework, frequency of outlet use and number of outlets
A cistern measures 900mm x 900mm x 800mm and has a working capacity of 70% when filled to its shut-off level. How much water does it store?
260 litres
453 litres
648 litres
722 litres
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 any maintenance
Pump seals replaced and drive shafts lubricated annually
Impeller cleaned and pump vented half yearly
