Module 2 Valves And Taps Flashcards
What are stop valves?
They are used on high pressure water mains, they are designed with a rubber tap washer which gives a positive shut off under high pressure, they are slow close valves which slows down water to prevent water hammer
What are gate valves?
They are used to control the flow of fluids in low pressure systems such as distribution pipework from storage cisterns or central heating systems,
What are draw off valves?
They are used to drain boilers cylinders selection of pipework etc… They are usually fitted at the low point in plumbing and central heating systems
What are valves and taps defined as ?
They are devices designed to regulate open or close the flow of liquid or gas in a pipeline, they should be made from brass or other corrosion resisting alloys
What is a lever valve?
It is favoured on gas lines can also be used instead of a gate valve on low pressure water systems it’s not suitable for mains pipes
Bib taps what are they??
The are fitted to the wall with a back plate, used on Belfast sinks and in Europe most commonly, they are often used outside comes in chrome and plain
Hose Union bin tap explain it?
Must have a double check valve, also a service valve should be fitted upstream of the check valve
Define pillar taps?
The are manufactured with long inlet threads which allow them to be fitted through sanitary appliances to be clamped in positions, they are designed to make sure an air gap is allowed to prevent back siphonage
What should be done to taps before fitted?
They should be CRACKED so the are not sealed as tight
What are mixer taps?
They are designed to deliver hot and cold water through a spout,
What are the two main designs of mixer taps?
SINGLE outlet mixer and a DOUBLE outlet mixer
Where are single and double outlet mixer used?
Single is used when the water is of equal pressure hot and cold,
What’s a draw back of mixer taps?
The o ring tends to wear and needs replacing
What are service valves??
Can be known also as penny or balloon,there use is for single appliances such as basin taps, they isolate for for repairs or replacement, they are restricted to a 10mm bore in the centre
What are plug valves?
They can be fully opened or closed by turning it 1/4 of a turn, so can be closed very quickly they are usually used on gas lonesome drain points on water systems
