Damaged cylinder outlet

[jakefouro]

It is with great embarrassment that I post this request . Today while fitting a new dual coil cylinder in the hotpress I overtightened a 1 inch fitting to one of the threaded outlets of the cylinder. Thankfully there was not a major leak as the cylinder was filling at the time. However, the whole joint is now loose - I believe I have sheared off most of the threaded outlet beyond the large nut holding it in place. I have not removed the 1 inch fitting to inspect the damage as the threaded outlet would completely shear off.
My question is: can I solder the 1 inch fitting to the large nut on the threaded outlet? What other options do I have if any?

Thanks in advance.

 

[weseeyou]

don't know your own strength Jake !

Picture would help but basically your cylinder seams are all soft soldered and if you apply too much heat to a fitting near he base seam you are likely to lose solder from a seam and make it worse.

Trim the damaged thread remove the nut and screw a 1" Female Coupling on in place of the nut

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[jakefouro]

Sounds like a good plan weseeyou - I presume I would need to empty the cylinder to try this?

 

[weseeyou]

unless you want a flood

seriously I hope you have installed a drain cock on the cold feed where it enters the cylinder ?

If the broken boss is on one of the coils then you might get away with using a few absorbant towels .You'll have to weigh up the risk against 20 minute draindown and refill.(provided you put that draincock in) otherwise you'll need to syphon it out

 

[Softus]

I'd remove the cylinder completely, then buy and install another one.

Then I'd get the damaged one repaired by the manufacturer and ask them to warrant it. Then either keep it for the next job or sell it on eBay.

You might lose some margin on the exercise, but customer disruption will be minimised and the cost to you will be far less than the potential cost of damage resulting from a serious leak from the top of the cylinder.

 

[jakefouro]

Ok weseeyou, took your advice and drained the cylinder - inspected the damage and there was enough thread left on the boss after removing the locking nut to grip a 1inch coupling. Problem solved although there is a tiny leak between the coupling and the cylinder which I must sort out later. Thanks again.

 

[weseeyou]

well done. You'll need to monitor it when it gets to full temp for a while. The weep will probably stop but may get worse. If you are using ptfe tape give the fitting a nip no more than 1/4 turn at a time and give it a while to settle.
I take it that this is your own installation and not in a client's house ?

 

[jakefouro]

Yea, I'm putting in a boiler stove and changed to a dual coil cylinder. I'll drain the cyliner once more to try to fix this leak - I will use the heavier pfte tape used on gas fittings on the joint - hopefully that should sort it out.

 

[Agile]

Picture would help but basically your cylinder seams are all soft soldered and if you apply too much heat to a fitting near he base seam you are likely to lose solder from a seam and make it worse.

I always thought that copper cylinder joints were braized with a high temperature solder material?

A common cause of leaks is that they leak on the heating coil where it comes through the hole in the cylinder and tightening the nut does not stop it.

I have often wondered if anyone has ever succeeded to solder the boss to the cylinder from the outside to solve the problem? ( With the cylinder empty obviously and ideally on its side! )

Tony

 

[jakefouro]

Yea - Thats where I have the leak, Agile and as you say tightening the nut is not having an effect. Ah well, will have to drain down the cylinder again and keep trying.

 

[weseeyou]

you are trying to make the female coupling do two jobs at once here. Seal on the straight part of the threaded portion of the coil and also seal and clamp the coil to the cylinder.
Make sure that the female coupling can screw onto the coil thread sufficiently to tighten against the face of the cylinder in place of the nut that you have removed.
The threads are both straight not tapered so you need to use plenty of ptfe ' remake the joint as many times as you have to before you are confident it will seal.

I would let the cylinder get to temperature before abandoning what you have already done. The leak may stop

 

[jakefouro]

Ok - joint appears to be sealed at last - I found a rubber washer that fitted over the threaded boss and with lots of tape on the thread. As you say weseeyou, it weeped for a while but stopped after cylinder heated up. Stayed sealed after cooling down.

 

[weseeyou]

Ace
wel done. Bit of a bodge but it'll probably outlast the cylinder

 

[Softus]

Ok - joint appears to be sealed at last - I found a rubber washer that fitted over the threaded boss and with lots of tape on the thread.

Rubber washer? On the top outlet of a cylinder?!

That's going to last no time at all.

 

[weseeyou]

Ok - joint appears to be sealed at last - I found a rubber washer that fitted over the threaded boss and with lots of tape on the thread.

Rubber washer? On the top outlet of a cylinder?!

That's going to last no time at all.

well that was a really helpful post wasn't it softy

whats the matter ? upset because you didn't offer any solution ?stop following me around like a lovesick teenager