How to seal this plumbing joint?

[blackrose]

The thread on this joint (hot water out) for my new water heater is on a sort of ferrule cylinder that slides up and down on the pipe. It came with a fibre washer for the end of the pipe but that doesn't stop water getting between the threaded cylinder and pipe. How am I supposed to seal it? 

 

 

[nicknorman]

The seal is between the flared end of the pipe and the female receptacle. If it leaks check for lumps and bumps on the male or female bit, and look closely for any possibility of the pipe having split. With a fibre washer not much force should be required to seal, but you’ve no doubt noticed the square section on the pipe and the flats on the screw bit, which are designed to help you tighten it up. You could bodge it with some plumbers gloop (boss white etc) but I can’t help thinking there must be an underlying issue making it leak, better to fix that than cover it up with gloop.

 

Looks to be a bit of damage on the flared bit, but hard to see exactly.

Edited July 26, 2018 by nicknorman

[Wanderer Vagabond]

I'm no expert so may be completely misunderstanding the problem but would PTFE tape on the thread cure it?

[nicknorman]

47 minutes ago, Wanderer Vagabond said:

I'm no expert so may be completely misunderstanding the problem but would PTFE tape on the thread cure it?

No, but it might cover the problem up for a while! That type of fitting is not designed to seal via the threads. In fact most types of fitting aren’t, unless they have a tapered thread.

Edited July 26, 2018 by nicknorman

[blackrose]

Ok thanks. Yes I guess the fibre washer should seal the face of the pipe against the inside of the female fitting and then water couldn't get between the threaded cylinder and the pipe. 

 

 

[nicknorman]

Just now, blackrose said:

Ok thanks. Yes I guess the fibre washer should seal the face of the pipe against the inside of the female fitting and then water couldn't get between the threaded cylinder and the pipe. 

 

 

Correct.

[sharpness]

A 1/2" tap connector, bent or straight depending on pipe runs or even a flexi tap connector would fit on that I think. A flexi might restrict the flow though unless you get a full bore one.

[PaulJ]

A rubber seal in place of the fibre washer may well work better.

[MtB]

3 minutes ago, PaulJ said:

A rubber seal in place of the fibre washer may well work better.

 

Either will do.

 

A photo of the fitting into which the OP is attempting to fit this pipe would probably reveal why the joint leaks. 

[Boater Sam]

With a tap connector you may have to file off the shoulder that holds the washer at the end to make a flat face, the shoulder will not go up inside the flanged end of the pipe you show.

Or use a Yorkshire #2 female bsp brass fitting and more than one washer until it seals.

[Ex Brummie]

This fitting is essentially a tap connector. This would be sealed by a 'pilock' washer; a narrow fibre washer that seals against a flat face as in a female threaded 1/2" -15mm coupler. Using a normal fibre washer or rubber washer can be restrictive to flow.

[Neil Smith]

A smear of silicone on both sides of the fibre washer will seal small damaged surface areas on the fittings.

 

Neil