WorksheetsUnit 205: Cold water systems — Worksheet 4: Components
Total questions: 11
Worksheet time: 6mins
Which statement best defines backflow in cold water systems?
Water flowing from the source to fixtures under normal pressure
The reversal of intended water flow, allowing potentially contaminated water to move back into the supply due to pressure differences
Water circulating within a closed heating loop
The slow seepage of water through pipe joints without pressure changes
Which statement best defines back syphonage in cold water systems?
A forward flow caused by increased outlet pressure
A reversal of flow created by negative pressure that draws water back from an outlet or appliance
A pressure surge that increases flow rate in the main
A controlled return of water for recirculation
In the fluid category table for backflow risk, the description for Category 3 reads "Fluids representing a (____) health risk, that aren't suitable to be drunk." Which word correctly completes the description?
slight
significant
serious
negligible
In the fluid category table for backflow risk, the description for Category 4 reads "Fluids representing a (____) health risk, containing toxic substances." Which word correctly completes the description?
slight
significant
serious
moderate
In the fluid category table for backflow risk, the description for Category 5 reads "Fluids representing a (____) health risk, containing pathogenic organisms, radioactive, faeces." Which word correctly completes the description?
slight
significant
serious
minor
Select the three things that insulation on cold water systems is intended to prevent.
Freezing of pipework
Heat gain into cold water
Condensation on pipe surfaces
Increase of static pressure
Air entrainment at outlets
Select two applications where a single check valve would typically be used in cold water systems.
Cold feed to a domestic water heater to prevent reverse flow (Category 2 risk)
Outdoor hose union tap supply
Supply to a washing machine
Supply to a dishwasher
Make-up water to a closed heating system expansion vessel (Category 2 risk)
Select two applications where a double check valve would typically be used in cold water systems.
Outdoor hose union tap supply
Supply to a washing machine
Cold feed to a domestic water heater
Supply to a dishwasher
Make-up water to a closed heating system expansion vessel
A double check valve is used to protect Category 1 water (wholesome water) from which other category of water?
Category 2
Category 3
Category 4
Category 5
When protecting Category 1 water (wholesome water) from Category 5 water, Water Regulations state mechanical protection must not be used. What method is used to prevent backflow or syphonage in this case?
Single check valve
Double check valve
Reduced pressure zone (RPZ) valve
Air gap to atmosphere at the point of use
What prevention of backflow must be maintained on these sanitary ware items: basin, bath, sink, WC float operated valve, WC overflow to pan rim?
Single check valve
Double check valve
Air gap to atmosphere
Closed recirculation loop
