Ball valve, Part 1, Part 2, Torbeck or what?

[JohnD]

Which should I use when replacing old one in the mains-fed F&E tank in the loft?

 

[John_D]

Hi Feed and expansion cistern can use part 1 or part 2 ball valve.
Cold water must use part 2 valve to conform with water regs.

 

[JohnD]

Thanks. What's the difference?

Are you impersonating me?

 

[John_D]

Impersonating not a bit really wierd to see you there.
part 1 valve has a straight arm and flows out of the bottom of the brass
part 2 valve has a bent arm and a plastic piece on top to divert the water downwards

the part 1 is not allowed for cswc as it doesn't provide enough clearance for water regs

 

[JohnD]

thanks, I can see why, now.

 

[ChrisR]

F&E tanks have to use part 2, not part 1
Toilet cisterns can use part 1.

Now tell me why that's wrong?

 

[BoxBasher]

For use in a WC cistern valves should be Part 2, 3 or 4. (Part 1 is acceptable in conjunction with a double check valve).

For use anywhere else they may be Part 1, 2, 3 or 4.

The only condition being that if any part of the valve may become submerged whilst overflow is in operation then a Part 1 must have a DCV fitted immediately upstream.

 

[JohnD]

because some cisterns are fed off the mains which could therefore contaminate drinking water from back syphonage under combination of fault conditions?

All mine seem to be the ones with a plastic bridge over the top, which seems to be the right kind. Some are Torbecks with the perforated polythene tube dangling down for quietness.

 

[Nige F]

plastic bridge over troubled water ...part 2.........ffs let`s all go back to using Croydon pattern..........and get them made in China (peoples republic)and fit china syphons (doulton, Royal) or

 

[ChrisR]

For use in a WC cistern valves should be Part 2, 3 or 4. (Part 1 is acceptable in conjunction with a double check valve).

For use anywhere else they may be Part 1, 2, 3 or 4.

The only condition being that if any part of the valve may become submerged whilst overflow is in operation then a Part 1 must have a DCV fitted immediately upstream

That's not what I learned on the water regs course, a few years ago.

The reasoning about the WC, (part 1 OK), was that the water in the wc cistern should be clean - a big air gap from the foul stuff. Maybe they realised that people lob all sorts in there, hence changed to part 2?

The bit about "if any part of the valve might become submerged" sounds like a bolt-on condition too. Has it changed?

 

[BoxBasher]

That's not what I learned on the water regs course, a few years ago.

The reasoning about the WC, (part 1 OK), was that the water in the wc cistern should be clean - a big air gap from the foul stuff. Maybe they realised that people lob all sorts in there, hence changed to part 2?

Part 1 valve is not deemed to provide sufficient backflow prevention in a WC cistern due to the relative height between discharge (at bottom of valve) and overflow. The water in the WC cistern will usually be a maximum fluid category 3 for which a DCV will suffice (the DCV taking the place of the valve for backflow prevention, the valve remaining solely as a control on the flow of water)

The bit about "if any part of the valve might become submerged" sounds like a bolt-on condition too. Has it changed?

Not a bolt on condition, just a clarification. Nothing has changed.

 

[jogger321]

We were told on our C&G course (which of course means I know nothing)..that whilst you can still buy part 1..they are illegal to fit...

 

[BoxBasher]

We were told on our C&G course (which of course means I know nothing)..that whilst you can still buy part 1..they are illegal to fit...

Already been covered. They aren't illegal to fit... but they aren't a legally acceptable form of backflow prevention on their own - they must be accompanied by a DCV.

 

[keego]

I've always assumed that if it was tank fed then you could use a part 1 & anything fed off the mains required a part 2.

 

[corgiman]

as long is it aint a part 4 mate