Cutting into wall-mounted CH copper pipe ?

[Jethro_uk]

SO following the sage advice here, fitting an external expansion vessel seems to be the way to go.

Seems they need to be plumbed into the CH return pipe ?

On my boiler, this is a larger (1" ?) copper pipe which runs through the ceiling into the boiler, and is fixed by wall mounted clips, so it's about 8mm from the wall.

I can't see anyway to lift it off the clips without some straining which I would rather avoid.

Presumably I need to insert a "T" piece into the pipe ... I'm happy to use pre-soldered bits (have done this before elsewhere, with an asbestos mat behind). But is there a way to cut out the necessary section without disturbing the pipe (too much) ?

[GB]

ANGLE GRINDER!!!!

More mundanely: Reciprocating saw or hacksaw. Very hard to get a nice square cut though.

None of the pipe cutters will fit in 8mm.

[GB]

If you can spring the pipe away from the wall a bit.

[Jethro_uk]

I'll do some exploring ... I might be able to tease the pipe a few more mm away.

I could always tap into the pipe the other side of the ceiling (in the loft). But that seems to me to be replacing an inaccessible component that has failed with another inaccessible component.

Thinking about it (in for a penny ...) if I disconnect the pipe from the bottom (where it goes into the boiler) then I will probably have enough play to run a pipe cutter around it.

[The Natural Philosopher]

disconnect from boiler and strain it.

Copper doesn't mind strain.

[Tim Watts]

Hacksaw is fine - if you're soldering or using compression, a perfectly square end is not necessary.

[Jethro_uk]

Ah, TX ..

I'm probably a tad anal about wanting a perfect square cut. Maybe too much reading about pushfit connectors. (I already know that copper is preferred close to the boiler).

One of the most amusing threads I read on this newsgroup was ages ago ... probably an old-school troll. They insisted that the reason their pushfit was leaking had nothing to do with the fact that they had ignored every single directive in the instructions about not using a hacksaw ....

[The Natural Philosopher]

That's what I said.

The number of times I have had to relearn the lesson 'trying to dismantle it less always leads to more work eventually'

Taking off the entire back axle to get seized brake drums and hydraulics apart.

Much easier.

[Bob Eager]

The famous Drivel hacksaw...

One of the tiny pipe cutters would fit, with a push.

[Jethro_uk]

+1

[Tim Watts]

Not just preferred - mandated usually withing about 600-1000mm of the boiler - you have to check the manufacturer's instructions :)

Yes, pushfit needs a rounded square cut, so pipe cutter. Nothing else cares - but compression would prefer you had no deep scratches where the olive is.

aka Dribble/Dr Evil

[Dave Plowman (News)]

Hacksaw and some skill. But it doesn't need to be 100% square. However since there will be waste when inserting a T piece, you can file it square. But might be more of a problem moving the tube up or down to insert the T piece, unless one end can be disconnected.

[tabbypurr]

+1

Compression certainly cares. It needs zero outward flash and zero distortion - you don't get those with a hacksaw.

An expansion vessesl can go anywhere, can't you find anywhere easier?

NT

[newshound]

But if you can get into the loft to fit it, it's not inaccessible is it. The other thing I would suggest is fitting a ball-valve and a drain point on the branch so that you can isolate and drain it easily if you want to check the pressure and/or recharge it some time in the future. This is what I have done, anyway. Just given it its first check / recharge in about 15 years.

Important not to accidentally leave it valved off of course.

[Jethro_uk]

AH, well one end goes into the bolier, so can be disconnected making it free floating ...

[Jethro_uk]

cutter-28mm/84356

True - but by that token then technically the original expansion vessel isn't inaccessible. The section of loft involved is a ****ing pig to get to - need to squeeze through a tiny gap followed by a 15 metre crawl over joists.

Ah, good tip ! Thanks.

:)

[www.GymRatZ.co.uk]

Don't see why particularly, it's to allow expansion of the water in a closed system. I'm pretty sure mine is fitted next to the boiler tapped into the main flow pipe, presumably as it could only be fitted to the wall on the flow side of the boiler. in fact it's bolted onto the over-pressure blow-off safety valve thing that vents to the outside so it must be on the flow rather than the return. Been there for 10 years without any problem oh, AND it was fitted up-side down with the inflation valve at the bottom (not fitted by me I should add) :)

"Pressure in a liquid remains constant" and all that. Just fit it somewhere in the system that is always "live"

[Harry Bloomfield]

Tim+ formulated on Wednesday :

Agreed, no reason why it wouldn't work, but for longer life it is better installed in a cooler section of pipe. Hence in a return leg.

One way to ensure 'cooler' would be to fit it on a T, with a pipe spacing it away from the rest of the pipe.

[dennis]

You have tried to recharge the original one? Remember than when recharging that water is incompressible so you have to have somewhere open to let the water out as you pump the air into the expansion bottle. If you don't then you will only get a small amount of air into the expansion bottle and it will appear to not work. When first fitted they are full of air and have no water in them. After a recharge they should also be ful of air with no water in them. They only get water in once you pressurise the system.

[dennis]

You do need to de-burr though.

A multitool will cut it with ease.

You can get a wire saw and use that if there is only a mm or two.