New cold water loft tank - tank connector problem

[David Hearn]

I'm after some advice as to how to sort out a problem I've got myself into.

Got a new 50 gallon cold water loft tank which I'm in the process of fitting. I was trying to use brass 22mm compression tank connectors

which I now question the wisdom of. I drilled two 29mm holes to fit the two feeds (one to hot tank, other to cold). I'm also replacing the 4 gallon CH header tank - so drilled 29mm hole for that one too.

These connectors have two 'pins' or lugs on the back (this link shows similar product's lugs:

- consequently, when trying to do up the compression joint, I cannot stop the connector turning before the olive is compressed - even using a pump wrench on the lugs at the back.

You can get a special tool

but having done up other 22mm compression joints and seen the force I've needed, I fail to see how it could adequately work (without two pairs of strong hands).

I've seen people talking online about SpeedFit 22mm tank connectors being the way to go, and I thought that would be ideal - however, I then found that they require 36/38mm holes cut in the tank. I'm concerned whether I could cleanly expand the existing hole - the hole saw worked fine the pilot drill fitted, but I'm concerned whether I could keep it in one place without the pilot having anything to centre on.

I've also seen other 22mm compression tank connectors (which I would hope would fit existing 29mm hole) which have hex shapes on the rear of the connector:

I'm concerned that they're quite slim hex nuts, and whether I could properly get the compression joint made without the inner spanner/wrench slipping and damaging the tank. Would these fit the same hole as the one I got?

I've seen solder ring tank connectors

- presumably the nut goes inside the tank) - but at £14.99 each (I need

3), it's very expensive! Would this fit the existing 29mm hole?

I've also seen a copper push-fit tank connector

- again I presume the nut goes internally). Would this fit the existing

29mm hole? This seems a more reasonable price, but would I need any tools? I've not used any type of push-fit before. Can I just cut a 22mm copper pipe and push in? Is this one demountable (with/without tools)?

I really appreciate people's advice on this one. I'd allowed the weekend for the job, but it took longer. Currently we're without hot water until it's finished.

Thanks

David

[fred]

In article , David Hearn writes

Make your own tool, 2mm flat bar with 2 holes drilled to match the lugs. I was going to suggest putting any old bit of flat bar between the lugs but that could result in a bit too much shear given the extra leverage.

The 22mm compression shouldn't take too much force to do up, if it does then smear a tiny amount of silicone grease round the threads and around the outside of the olive to lube it up as it tightens. If no silicone grease you could use a wrap or two of ptfe tape (only to lube the threads and olive outer) but if anyone sees that you will probably be branded as the punter who doesn't know how compression fittings work.

I've not needed to go this far before and assume that once you have the tool made the joint will nip up fine.

[Andy Cap]

If you decided to go for the Pushfit you could enlarge the holes with a conical cutter like this Ebay - 221111840773

Andy C

[Dave Liquorice]

Surprised, compression is normally just hand tight plus 1/2 to 3/4 of a turn. As others have pointed out have you lubricated the olive/threads, I'd use a smear of Boss Green rather than silcone grease or PTFE tape.

[Grimly Curmudgeon]

You tighten up the connector on the tank first - tight as f*ck. You then use a dummy straight or angle connector to tighten the olive on the pipe then use that tightened olive/pipe on the tank connector, while keeping the tank fitting from turning by using the tool on the back of it - either use the special tool or a large adjustable spanner closed down to fit the lugs.

Use a wrap of ptfe or a smear of Boss White or similar on the olive.