Nevo water valves-can they be used “before” a stop tap?

[mart]

I have a domestic stop tap to change soon. It involves isolating the water supply on the street , which invariably means turning the neighbour’s water off for a while until the job is done. I have thought of fitting a nevo isolating valve just before the stop tap in the house so that I don’t have to isolate on the street if there is a need to isolate the supply in the future.

The question or concern is will a nevo valve hold the water pressure at that point when isolated using the nevo only?

 

[upinsmoke]

Hi i dont know what a nevo valve is,but why not put in a standard brass stopcock as that is what the water regs requires. If the valve you refer to is an electric valve it will do but i would still want a stopcock as well.
I did a job once for an old girl who had an electric valve, and as they shut down fast being operated by a solinoid switch, if the water is flowing fast as was the case when shut down it can rupture the pipe from the outside stopcock,as it did. Luckly it was out in the street so it was down to the water board to fix. The guy said this was quite common with electric valves, the sudden action causing a shock wave that can spilt elderly rising mains

 

[mart]

Hi i dont know what a nevo valve is,but why not put in a standard brass stopcock as that is what the water regs requires. If the valve you refer to is an electric valve it will do but i would still want a stopcock as well.
I did a job once for an old girl who had an electric valve, and as they shut down fast being operated by a solinoid switch, if the water is flowing fast as was the case when shut down it can rupture the pipe from the outside stopcock,as it did. Luckly it was out in the street so it was down to the water board to fix. The guy said this was quite common with electric valves, the sudden action causing a shock wave that can spilt elderly rising mains

Hi, you have not read my post correctly. I said I was thinking of putting a (nevo) isolating valve before the stop cock, not instead of a stop cock.

My question was whether this would hold the mains pressure. If it is capable of holding mains pressure at this point it would be an alternative to turning the water supply off in the street (in case I need to change the stop cock again a few years down the line-they have a habit of leaking). Hope that makes it a bit clearer. Thanks.

PS, here is a Nevo isolating valve-
http://www.screwfix.com/p/15mm-isolating-valve-pack-of-10/32802

 

[upinsmoke]

Hi yes it would hold mains pressure, but if you look though the valve you will also see that it will restrict flow, these valves are known as ball a fix valves and are ment to be used only to isolate taps.
What would be better is a Full Bore Lever Ball Valve ,These are gas and water approved well made and have the advantage as the name says that when open they do not impinge on the water flow.
In my plumfix cat 22mm £5.24 plus vat.
Hope the helps

 

[mike os]

no you cannot use these before the stopcock... well you can if you want it to reduce the flow and probably fail when you need it.

a full bore ball valve would do... but why not just fir a new stop tap like everyone else? if it is leaking after a few years it is iether a crap product on not installed correctly, they last decades

 

[the snooper]

what is the point ? how far do you go fitting isolators before isolators ie stopcock if the isolator fails you still have to turn off in the street and what are the chances of a new stop tap failing ? they last for years its just another possible problem for the future

 

[Robotstar5]

but why not just fit a new stop tap like everyone else?

Well nearly everyone else, our plumber just replaced the perished washer with a new one

 

[mike os]

Well nearly everyone else, our plumber just replaced the perished washer with a new one

quite...sledgehammer & wallnut comes to mind..

 

[mart]

OK thanks for the advice. I had not heard of the full bore valves so have learnt something there.

I acknowledge what you mean regards "sledge hammer to crack a wall nut". Yorkshire water came last week to clear-out the mud that was covering the stop tap that is located about 4ft down in the chamber on the street. They tried to turn this stop tap and something broke. The mains supply started to flood the pavement. Next, Morrison contractors arrived with a mini digger on a trailer, and the area ended up like Fred West’s back yard.

I guess that little job would not have been cheap. The guy from YW said it is because these taps are not used often. I do know the fire brigade go around checking their hydrants, perhaps for a similar reason

 

[brightspark]

u would be suprised how many stop taps dont work either stuck or leak after turning inside house and on the street . by the time u go to turn of in an emergency its 2 late / flooded property the moral of story is check them before it happens. i go to earth bond them in houses and the customers dont even know where they are

 

[dannyp]

fire bregade used to go round checking hydrants, they'd check the valves work, clean them out and even paint the covers so they chould find them.

that dosent happen anymore

seen them looking for one for about 10 minutes when they eventualy found it they chouldn't get water out of it and there pipes wouldn't reach the next one. the house they were going to put out was about knackerd by then

 

[dannyp]

as for valves simpelest one first, it's less likely to fail. no need for multi valves ether really double the number of valves you've just doubeld the chances of failure.

when used to work on the building 1st thing we'd do is check the valve outside ( last thing you want to do is find a random pipe that has no l,ogical reason to be where it is and flood the place )