Mains stopcock replacement

[20pictures]

Discovered that the gate valve that serves as mains stopcock for my flat does not close fully, leaving water under pressure passing through. I do not want to force it as last week I sheared a gate valve doing this.

I have given notification to other residents & arranged for the mains water riser to be shut down for next Monday morning. I was thinking of replacing it myself but with a 'proper' 22mm stopcock. The pipes either side are steel & copper with little room for springing.

Any advice on fitting or the possibility of getting the gate valve to work?
I have tried opening/closing many times.

 

[ChrisR]

Bin the gate valve. Alarm- steel pipe: most common valves are designed to connect to copper. Go to a real plumbers merchant and ask for a Conex or Peglers stop cock. Screwfix sell them I think. Cheap ones may fail in a year or three.

 

[20pictures]

I'm assuming the steel pipe works in the same way & connects with an olive fitting.

 

[20pictures]

Conex or Peglers stopcocks seem very hard to get hold of. Been to 3 plumbers merchants this afternoon with the best offer being a Conex coupler!

I take it the recommendation is because of their durability & not because it is a steel to copper connection?

 

[AdamW]

Screwfix sell Pegler stuff: http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=20182&id=18986

My local builders' merchants is a Buildbase, they sell Pegler brassware too but it costs twice as much as Screwfix.

Plumbcenter also sell Pegler, they have brances all over the country.

 

[MANDATE]

I've never seen a steel pipe fitted to anything using an olive. It is more likely threaded. Couldn't you leave the existing valve in situ and fit another one with compression fittings above it.
Although I know it does not close fully, does it cause any real problem.
I say this because my son had a similar situation and while we worked on the pipe work we closed the valve and opened the kitchen tap which allowed the leaking water to drain away.
When you have the water off, could you not remove the centre section of the valve to examine the gate and see if the problem is down to wear or maybe sediment.
Don't get yourself into a situation that you can't resolve, the other residents will not be happy

 

[20pictures]

Thanks for all the advice. The day has been postponed whilst I consider my options...

 

[MANDATE]

Just one other point, there is a difference between a stopcock and a gate valve. The stopcock incorporates a rubber washer and acts as a one way valve to prevent back flow and any contamination, so it is important it is fitted in the correct direction. The gate valve is not one way and is not supposed to be used in place of a stopcock.