Honeywell automatic bypass

[mike42]

Hi

I bought one of these (right-angled version) and noticed that the original nuts on the 22mm pipework didn't fit. Then I saw on the body of the unit "3/4". Testing it I put some new 22mm pipe in and tightened up the nut but it seemed I needed to tighten really tight in order for the olive to grip the pipe and stop it rotating/moving. Obviously 3/4 of an inch is quite a bit smaller than 22mm but I'm guessing maybe there is some subtly about internal/external diamter and in fact these fittings are compatible?

So the question is, is this thing ok to fit to 22mm (just tighten up more than usual?)

https://www.amazon.co.uk/Honeywell-...714791&sr=8-2&keywords=automatic+bypass+valve

 

[Steelmasons]

Your post makes no sense.
So you have a 22mm ABV although the pipework you are fitting it too is 3/4"?

 

[mike42]

The ABV is 3/4 inch and the pipework is 22mm. Sorry that wasn't clear.

 

[Steelmasons]

ABV is 22mm.
Had the ABV been 3/4" then you wouldn't have been able to fit it to pipework.
Your pipework is possibly 3/4" so you will require some 3/4" olives..

 

[mike42]

But why does it have 3/4 written on both sides of the valve?

 

[Steelmasons]

https://www.amazon.co.uk/Honeywell-...714791&sr=8-2&keywords=automatic+bypass+valve

It clearly states 22mm.

 

[Dan Robinson]

I'll have whatever the op is having.

 

[mike42]

Yes that's why I bought it but on the valve body itself is written "3/4" - no mention of 22mm. And as I say, it seems to require a heck of a lot of force just to stop the copper tube falling out of the valve.

 

[Dan Robinson]

What is the part number of the valve?


What does it say on the underside of the nuts?

 

[oldbuffer]

The "3/4" on the body of the valve refers to the thread on the inlet and outlet, which is 3/4" BSP. The inside of the inlet and outlet is 22mm in diameter, as is the hole at the non-threaded end of the nuts and the olives. It sound as if you have 3/4" imperial pipe, which will need 3/4" - 22mm adaptor olives to fit the valve properly (e.g. https://www.stevensonplumbing.co.uk/compression-olives.html last item on first page).

 

[mike42]

Thanks very much oldbuffer much appreciated! I'll double check the pipe I was testing with but thought it was 22mm - I don't its decades old and I definitely haven't had a need in the past to buy imperial pipe. I have some other pipe that is definitely 22mm so will check with that. I guess worst case just bung it up a bit with some jointing compound, tighten and hope for the best!

One last thing, is it correct to the say then that 22mm fittings (those for 22mm pipe) can still have either 3/4" nuts or 22mm nuts? That would explain why the nuts on my other 22mm fittings don't fit this Honeywell ABV.

 

[oldbuffer]

1. I wouldn't "bung it up and hope for the best" - I've seen too many floods as a result. Get the correct conversion olives and fit them.

2. Honeywell tend to use a different thread from other makers, for example on their motorised valves. Its an American thread (and probably not BSP as I suggested earlier). I did ask them once and, from memory it is an extra fine unified thread). That's why 22mm compression nuts from other makes won't fit.