Surrey Dave
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| posted on 16/8/07 at 05:52 PM |
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Gate Valve vs Stopcock
Whats the difference can I use a Gate Valve for my main water stopcock?
My main stop cock is 40 years old and I would like to replace it.
(I realise this may be an invitation for some carry on type humour!! matron!!)
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ruskino80
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| posted on 16/8/07 at 05:57 PM |
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gate valves are not suitable for mains or high pressure,just install a new stop tap inline after the old one.job done.
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MkIndy7
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| posted on 16/8/07 at 06:04 PM |
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Also gatevalves often snap off after many years!
There probably cheeper as well!
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Peteff
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| posted on 16/8/07 at 06:11 PM |
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Gate valves don't generally have rubber seats in them.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Surrey Dave
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| posted on 16/8/07 at 06:41 PM |
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full flow
I would like to get full flow on the main feed so my combi boiler can do it's best with the hot water flow , what about those red lever cut off
valves, they are full bore, are they OK on the main water pipe?
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darrens
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| posted on 16/8/07 at 07:16 PM |
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hang on, a stopcock is actually a gatevalve
correct me if I'm wrong.
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Confused but excited.
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| posted on 16/8/07 at 07:25 PM |
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Ball valve will give full flow. Get a stainless one with ptfe seal.
Tell them about the bent treacle edges!
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darrens
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| posted on 16/8/07 at 07:28 PM |
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quote:
Originally posted by Confused but excited.
Ball valve will give full flow. Get a stainless one with ptfe seal.
ditto above
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MkIndy7
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| posted on 16/8/07 at 07:31 PM |
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Only certain ball valves will give full flow, most of the Cheepy Ballafix valves narrow to about 10-12mm at a guess, but there are more expencive
types, possibly "Peggler" make that are full bore and are physically larger.
I can see why being idealistic you might want a "full flow" valve.. but the first thing it will go through in the combi is a restrictor
of some sorts to throttle the outlet flow so you get a descent temperature out of the combi, they just Cannot warm up the full flow of water to
acceptable levels.
A mains stopcock and a gatevalve are different, even to look at a Gatevalve all the valve body is inline on a stopcock all the body of the valve looks
to be to one side as internally they are different.
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ruskino80
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| posted on 16/8/07 at 08:03 PM |
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agree with above.
check that the boiler cold input has not been throttled down to limit flow-but if it has it will have probably been set like that by the installer on
purpose to achieve good hot water draw off.
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BenB
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| posted on 16/8/07 at 09:13 PM |
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In my experience stop-cocks can handle mains pressure, gate valves can't.... they tend to leak when completely closed due to the lack of a
washer....
Just my experience...
If you need to be able to completely isolate the water supply you're best going for a proper stopcock and doing it properly....
And their method of failure is different... Stopcocks just jam solid, gate valve knobs rip off 
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ruskino80
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| posted on 16/8/07 at 09:25 PM |
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gatevalves and stoptaps/cocks only fail for 1 reason-----lack of maintainance,they should all be used a couple of times a year ie closed snd
reopened,to keep the moving parts moving-of course the reality is no one ever bothers-however keeps me in work so please ignore my advice
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MikeRJ
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| posted on 16/8/07 at 10:01 PM |
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Gate valves are rubbish IME, they always leak a little bit. Very annoying if you are trying to solder a pipe that is isolated by a gate valve and it
slowly fills up.
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40inches
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| posted on 17/8/07 at 09:33 AM |
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quote:
Originally posted by MikeRJ
Gate valves are rubbish IME, they always leak a little bit. Very annoying if you are trying to solder a pipe that is isolated by a gate valve and it
slowly fills up.
I'll second that they very rarely shut off completely and often jam shut with the wheel spinning freely.Nightmare. Thank god for freeze
spray
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