Drain Cock on Mains

[Dsp]

As per the title can you fit a Drain Cock on Mains Water??
i have always fitted a "T" fitting after the stopcock and put a Type A drain cock in so once isolated the whole system can be drained but been told today this is wrong anyone care to add their thoughts??

 

[Riley]

I was always taught to put one after stopcock. Maybe things have changed. Did they say why it was wrong?

 

[snowhead]

If the drain cock is between the stopcock and the meter then no you can't.

I've just had to remove one on an existing Commercial site at the request of Severn Trent following an inspection. It had been there since new (3years).
Drawing un-metered water was the concern I believe, although reason not stated other than contravention of the regs.
It wasn't the only non conformity.

 

[Riley]

Sorry I misunderstood I thought we were talking internal stopcock. I would never put one after the boundary stopcock

 

[Dsp]

Yes after internal stopcock and meter just for draining internal pipes and was told there for ch pressure not mains and it's only a washer seal??

 

[stevetheplumber]

rubbish

 

[Best]

It's regs over here for a draincock to be fitted after the internal stopcock. Rarely need to use them though, except if you are cutting into mains at a lower level to any outlets.

 

[jtsplumbing]

It shows in the WRAS book under system design & installation a drain tap above the internal stop valve

 

[AWheating]

sounds like somebody is tekin the mikkay out ya. Drain off cock after stop tap or meter is standard practice.

 

[Staffy85]

IIRC on the incoming main into building.... stopcock-None return valve - drain valve then what ever you want...

 

[IND_Nick]

Yes after internal stopcock and meter just for draining internal pipes and was told there for ch pressure not mains and it's only a washer seal??

Surely any tap is just a washer seal? As previously mentioned I always understood it as best practice to fit one after stop tap.

 

[SimonG]

Its regs for doc after stoptap.

 

[Dsp]

Thanks guys knew I was right I've always done it and will always do it's amazing how much bad work is out there

 

[plumben]

if im remebering correctly
Internal stop tap at 150mm off the floor and a d.o.c directly after it and or at the lowest point on the system to allow draining of the system.

although ive never used one on mains water as i usually just open the taps and anything thats left goes into a bucket once the pipes cut open

 

[Ric2013]

IIRC on the incoming main into building.... stopcock-None return valve - drain valve then what ever you want...

I thought the regs now didn't want a loose jumper on stopcocks on the grounds that a non-return valve in this location was undesirable?

 

[Staffy85]

I thought the regs now didn't want a loose jumper on stopcocks on the grounds that a non-return valve in this location was undesirable?

its been almost 10 years since my college days and thats how i remember it, how ever times do change....

 

[Ric2013]

Hey. The age of our housing stock, nearly all of it must be non-compliant as They keep changing Their minds. Yet somehow we seem to survive.

 

[Ric2013]

This actually came up as a matter of discussion with a colleague of mine the other day. We checked the regs and it doesn't actually say that you can't have a check valve on the supply pipe unless you have a specific need for expansion such as an unvented cylinder, although the regs do not always require a check valve in this location. They simply say you can't have a loose jumpered stopcock, without giving an explanation.

In his case, it made sense to fit one, as he was fitting a new supply to an old house which still had lead pipe and so at least his check valve kept the public water supply free from lead, even though the household still had lead pipe in the system.

 

[gassafe]

No one ever uses them anyway lol...