Gate Valve Mains Pressure Manifold

[DazJWood]

I have completely gutted my bathroom and on advice from my plumber I stripped out the old copper piping and I have laid plastic pipes to where the sink, toilet, bath and shower will go.

My plumber has installed a manifold system (if I'm saying it right!) in my airing cupboard. This takes a cold mains pressure feed and splits it and sends it out to all the cold supply plastic pipes. Equally there is a hot feed from my combi boiler for all the hot supply plastic piping. He has set this up using gate valves so each supply can be isolated if need be.

I have since read that gate valves should not be used for mains pressure and should only be used for low pressure systems. So has my plumber installed the wrong valves? He says that they can be used and he's installed loads like it and never had a problem.

If, as I suspect, they need to be changed, what do I change them for? Can I use just normal isolating valves (service valve types where you turn with a screwdriver)? I have seen the lever ones as well but the way my plumber has done this soldered manifold system the pipes are really close together and I don't think the valves would turn without hitting their neighbour one. Is another solution stop taps as well?

Also, should I be asking for full bore ones? Are most of these valves full bore anyway or do they need to state it?

Thanks in advance,

Daz

 

[migoplumber]

this will get a lot of posts. i use full bore lever valves because i like them. might be against some regs but gate valves will work just as well except for total shut off

 

[DazJWood]

Thanks for the reply but what do you mean by "except for total shut off"?

What problems would there be leaving the gate valves there? It says on a lot of sites that they are only suitable for low pressure systems not mains pressure.

Thanks

Anyone?

 

[MarkB]

Over a period of time you'll find that gate valves never quite shut off fully and will let by. They really shouldn't be used on anything other than gravity fed systems. If you do fit 1/4 turn valves than they should be full bore and if there's not enough room for lever operated ones you could use the "T" handled versions. (something like these http://www.pegleryorkshire.co.uk/taps_mixers.aspx?ID=10049&FolderID=113&button=General Information ) I use them when space is limited and they shouldn't take up anymore space than the gate valves.

Mark

 

[JSPM]

I concur with the posts above.

I have been to several houses of late where the clients complain of difficulty in turning off water when changing taps, draining down etc. Also when I have been doing install work the main problems I have with shutting water off are from gate valves. Unfortunately muck and lime scale so often builds up in the valve causing problems with them fully shutting off. Also some places recently have had them installed horizontally rather than vertically. Again in the horizontal position they are prone to "crud" build up particularly from Cold Water Storage tank feeds.

I tend to use full bore lever valves or "service valves" where needed rather than gate valves as I like to take the long term view with installations and maintenance.

Hope that helps and good luck.

Dave

 

[Robtheplumb]

I think from looooong back gate valves are only for low perssure...

Ball type valves are better but even these can sometimes let by a little bit