My latest compression bodge holding up....

[mike42]

So this afternoon's task for me was to replace a faulty gate valve on (for me) a big 28mm pipe that feeds the cold water from the tank. It started off very well, draining down was quick and unusually for me I managed to get the old valve off quite easily with no spillage. Even better the gap in the pipe was the right size for the new valve and the old olives came off no trouble. Brilliant, I thought.

I cleaned a the pipe a bit (not to the level that I would if soldering), put the new lever valve on with a smear of water hawk on both olives and tightened up. Filled up the water tank and noticed a small trickle. No problem I thought - just needs nipping up a little. Well even after tightening to the point of hearing squeeking metal and using quite a lot of force I was left with around one drip per 5 minutes.

I'm planning on draining down again in about a month to install a new tank connector and feed so I thought if I can contain it until then life would be good. I used lsx followed by self amalgamating tape wrapped round and it seems to have worked. I've never used or even seen denso tape - would that have been better?

I'm also been wondering why it leaked in the first place. How much jointing compound should one use? I just put a very thin smear on the olives but then I saw some of plumberparts' youtube videos and he seemed to spoon the stuff on. Also I normally use adjustables because my pump pliers are crap (ordered a decent one just now on Amazon) but the nuts were too big for all my regular steel adjustable spanners so I found myself using some really heavy, clumsy adjustable spanners I have. That might have had some affect on not putting the right pressure.

When I drain down I plan to use lsx on the olives (has never failed me yet) and if that doesn't work try 20 twists of pfte around the olives. Maybe if the pipe has a small dent in it (I didn't check that hard but nothing was obvious) I'l have no choice but to chop that pipe out and fit new?

 

[muggles]

Water Hawk is awful stuff, use Jet Lube V2 instead, it works much better

 

[dilalio]

@mike42 that's plumbing for ya
I changed a 30 odd year old immersion heater in a cylinder in a loft the other day... Hasn't worked for about 10 years and wasn't replaced earlier as last plumber couldn't get it out! Was pleasantly surprised at the relative ease I got it out with, but... Old gate valve on 22mm plastic pipe from cwsc let by whilst I was away getting new immersion heater and I came back to a bit of brimming over - not too much of a big deal as it was only just starting! More of a PITA was that the gate valve was kaput and it was so strongly graunched on to the pipe with the compression nuts that the jaws of my grips bit through the brass body instead of the nut undoing ! So, a bung in the tank, a new 22mm lever valve, a length of copper, a 22mm push fit coupling and an hours extra work and I was done

 

[mike42]

@mike42 that's plumbing for ya
I changed a 30 odd year old immersion heater in a cylinder in a loft the other day... Hasn't worked for about 10 years and wasn't replaced earlier as last plumber couldn't get it out! Was pleasantly surprised at the relative ease I got it out with, but... Old gate valve on 22mm plastic pipe from cwsc let by whilst I was away getting new immersion heater and I came back to a bit of brimming over - not too much of a big deal as it was only just starting! More of a PITA was that the gate valve was kaput and it was so strongly graunched on to the pipe with the compression nuts that the jaws of my grips bit through the brass body instead of the nut undoing ! So, a bung in the tank, a new 22mm lever valve, a length of copper, a 22mm push fit coupling and an hours extra work and I was done

Where did you get or what did you use for your bung? I've got a 22mm one I got from toolstation a while back but can't see any 28mm ones anywhere. I'd guess you either got it a while back or somehow made it yourself - if the latter then how?

 

[dilalio]

Where did you get or what did you use for your bung? I've got a 22mm one I got from toolstation a while back but can't see any 28mm ones anywhere. I'd guess you either got it a while back or somehow made it yourself - if the latter then how?

I used a Carrot

 

[durhamplumber]

I used a Carrot

That will be similar to the carrot and potato method loved by ex gas board plumbers then!