Using lever ball valve as draining valve.

[Ant1]

Hi all,

I am installing all the pipes for a new CH system, the lowest point is 1.5m under the floorboards which I have access to. For convenience I would like to use a 22mm lever ball valve as my draining valve (I am planning to purchase a full bore one) which I will connect to a 40mm waste through a reducer.

Considering that the valve will be in closed position at all time except when I drain the system, are lever ball valves suitable for such use? I am concerned that the valve might not be designed to be constantly shut and could eventually let some water through.

Thanks!

 

[dilalio]

A "lever" valve is exactly what you should use on a CH system as either an isolator or a drain cock.
They are full bore and don't need to be 22mm.
If the pipe you are connecting it to is 15mm, then just use that size.
Why connect it to 40mm waste?
If your pipework is 15mm at that part of the system, put in a 15mm Tee and then a 15mm lever on the branch of the tee and then 15mm pipe from the lever to outside.
If it's 22mm, get a 22 x 15mm centre tee and do same.
Drain from lever to outside can be plastic pipe... It's only for relief.

 

[Ant1]

Why connect it to 40mm waste?

This is because it is underneath a Victorian house in the crawl space and I only have access to 40mm waste pipe to drain (it would be hard to drill a hole in a 40cm hole, and since it is listed I cannot anyway).

The easiest way I found to drain from 22mm to 40mm waste is by:
1) Using a 22mm tee
2) Connect a 22mm full bore lever valve on the middle connection of the tee
3) Convert from 22m to 40mm using a push-fit overflow reducer

Would you do it that way?

PS: this is the first time this house is getting central heating (explaining the reason for not having a drain pipe already), currently there are storage heaters.

 

[dilalio]

Listed?
Can you not drill a hole (15mm) through an exterior wall (front or back) and tee off from a (yet to be fitted) radiator tail, under the floor, to outside. Then just use a normal drain cock?
Without pics, it's hard to visualise your site layout.

 

[oldbutnotdead]

Ball valve is fine. Drainage point under the floor is fine long as you can get at it easily and it's above outside ground level (pushing water uphill doesn't work well).
Don"t forget to insulate all the pipes in the void...

 

[Nozzle]

For the avoidance of doubt do you mean one of these:
https://www.toolstation.com/ball-valve-pack/p18984

Or one of these:
https://www.toolstation.com/made4trade-lever-ball-valve/p57154

Both known as a "ball valve". When you say "the valve might not be designed to be constantly shut", and also that the subject title cotains 'level, and you wrote 'level' again in the message it suggests you think the first type, over the second... in which case no: not suitable for anything other than what it is designed for - a cistern!

Nozzle

 

[oldbutnotdead]

I was assuming 'level' was in fact lever- the valve that will be fine is the 2nd of @Nozzle 's links.

 

[Ant1]

For the avoidance of doute do you means one of these:
https://www.toolstation.com/ball-valve-pack/p18984

Or one of these:
https://www.toolstation.com/made4trade-lever-ball-valve/p57154

Both known as a "ball valve". When you say "the valve might not be designed to be constantly shut", and also that the subject title cotains 'level, and you wrote 'level' again in the message it suggests you think the first type, over the second... in which case no: not suitable for anything other than what it is designed for - a cistern!

Nozzle

Sorry this is a typo from myself, I am definitely referring to the second one, i.e. the Lever one and not Level. Glad to know it can be left in a closed position and not loose any pressure.

 

[Ant1]

Ball valve is fine. Drainage point under the floor is fine long as you can get at it easily and it's above outside ground level (pushing water uphill doesn't work well).
Don"t forget to insulate all the pipes in the void...

All those conditions are met, thanks!

 

[dilalio]

All those conditions are met, thanks!

And, as for a response to my last post?
Can you not send a drain leg to outside and use a standard drain cock?

 

[Ant1]

And, as for a response to my last post?
Can you not send a drain leg to outside and use a standard drain cock?

Sorry I should have replied, the house is split into 2 parts, the front and the back (i.e. an extension) with a thick wall between those. The easily accessible part is the front, unfortunately I cannot drill through the front façade as it is a listed building. Also I exactly identified the lowest point of the installation, in my opinion it makes sense to drain from that point, specially since there is an accessible waste pipe close back which is even lower.