Different isolation valves

[kdLeeds]

I am replacing a bathroom suite and using the opportunity to fit isolation valves to various pipe work, and find a confusing choice of valves.

Can someone please tell me the difference between them and what they are best suited for.

I have seen:

Stopcocks
Ball valves
Check valves
Gate valves

Thanks

 

[Gasguru]

Stopcocks are normally used on high pressure pipework eg incoming main.

Ball valves come in two versions - restricted bore and full bore. They are used on both high and low pressure systems primarly to isolate taps etc for servicing.

Check valves come in two varieties single and double check. They are normally used to prevent backflow and contamination of the water supply and to comply with the water regulations.

Gate valves are also used for isolating, the domestic types should only be used on low pressure (tank fed) pipework since they will not often shut off fully. Genuine BS graded gate valves normally have a larger bore.


Cheap ball valves are a waste of time - the chrome wears off the ball and the stem seals leak (especially the hot). Quality ball valves will be full bore, have PTFE seats and a proper gland nut. Like all things of quality you won't find them in the diy sheds.

 

[kdLeeds]

Gasguru, thanks for taking the time to explain. I'll get the full bore PTFE seat type from a merchant.

Thanks again