Gate valve as stopcock?

[kentishman]

Hi,

I have just had to replace my stopcock and have used a 22mm gate valve with a 22mm to 15mm reducer on one side. Could someone tell me if this is ok and that I'm not breaking any regs?

The incoming mains feed is black plastic pipe, the house side is 15mm copper. The flow is vertical through the valve.

Many thanks

 

[Softus]

Could someone tell me if this is ok and that I'm not breaking any regs?

Working from memory, which is fallible, the shut off valve must be of the screw down type, so a gate valve won't do.

Aside from the regulations it's a completely pointless thing to do, because within a very short space of time the gate valve will mature to the state where it's not capable of shutting off anything, let alone cold water at mains pressure. And that's if you buy an expensive one.

I can't stop myself asking you - why did you do this?

 

[Robster_1981]

Doesn't a genuine stopcock also act as a non return valve to prevent back syphonage into the main water supply??

 

[BoxBasher]

Doesn't a genuine stopcock also act as a non return valve to prevent back syphonage into the main water supply??

No.

I have just had to replace my stopcock and have used a 22mm gate valve with a 22mm to 15mm reducer on one side. Could someone tell me if this is ok and that I'm not breaking any regs?

Schedule 2 of the water regs, Guidance note 2.8:
Stopvalves for use above ground should be screwdown valves complying with BS1010

 

[kentishman]

[quote="Softus
I can't stop myself asking you - why did you do this?[/quote]

Having turned the water off and removed the old stopcock, I found that neither of the two different sized stopcocks that I had bought fitted... even though I was assured by the plumbers merchant who sold them to me that one of them would be correct.

It was late, the only shop open was Wickes, the only fitting they had was a gate valve, and the kids needed a bath!

Thanks for the other replies; Gate valve now removed and screwdown stopcock installed.

 

[Agile]

Can you tell us how you obtained a valve when the original two did not fit?

Gate valves are only designed to turn off low pressure supplies such as heating circuits for maintenance etc.

Tony

 

[kentishman]

Can you tell us how you obtained a valve when the original two did not fit?

Gate valves are only designed to turn off low pressure supplies such as heating circuits for maintenance etc.

Tony

The Plumbers merchant assured me that the incoming supply would be either 20mm or 25mm, and those were the sizes of stopcock he sold me. The incoming mains was actually 1/2 inch (outside diameter 21.4mm).

The 22mm Gate valve I sourced from Wickes fitted; and the adviser at Wickes said a gate valve can be used on incoming mains.

Thanks for your advice.

 

[Softus]

The Plumbers merchant assured me that the incoming supply would be either 20mm or 25mm, and those were the sizes of stopcock he sold me.

Normally I would agree with him, although you need a stop cock that suits the OD of the MDPE, with the appropriate olive too.

The incoming mains was actually 1/2 inch (outside diameter 21.4mm).

It's not advisable to state pipe dimensions using the inside diameter - that's a sure way to start confusing everybody.

What you might have there is Alcathene, if it's black pipe, rather than MDPE, which is blue.

The 22mm Gate valve I sourced from Wickes fitted; and the adviser at Wickes said a gate valve can be used on incoming mains.

Well, what's 0.6mm between friends.

As far as the 'advice' from the Wickes "advisor" goes - I can't think of any way in which someone could be more wrong.