Sealing parallel threads on external uv filter

[Easain]

I’m building a uv water treatment and break tank with pump in an outbuilding as we are on private supply. I cannot get these joints to seal with lots of ptfe tape. I have seen others on the forum use these joints so I presume it would work. Any advice appreciated . 

[Easain]

[Cpd]

Are you sure you have the right threads on both sides ? 
i used the same make valves as the fittings without a problem…. 
if your mixing brands of fittings this may be a problem but not something I came across. 
i have just checked my coupling between the two particles filters and it’s exactly the same as yours and mine does not leak, so I can only assume you have not got enough PTFE tape…..  strange 
 

Edited February 8, 2022 by Cpd

[markc]

Has to be a thread mix match

[Easain]

@Cpd I presumed everything was a parallel thread as there didn’t seem to be other option for connections - I seems that all my threaded connections are seeping even when plastic/plastic or plastic/metal. 

[markc]

Hmmm, did you wrap enough turn of PTFE to make the joints tighten up as then were wound in? Secret is to create a taper with the tape so the joint becomes progressively tighter and locks up before bottoming on the socket

[Easain]

@markc thanks, I think this will be my next thing to try yes .  had wondered if there was anything thicker then ptfe tape I could try? 

after connecting everything I realised I didn’t leave enough room between the roof to fit the uv bulb in so need to dismantle and re jig it all anyway ?

 

[Gone West]

3 hours ago, Easain said:

had wondered if there was anything thicker then ptfe tape I could try? 

There are two types of PTFE tape, the standard plumbing type and the gas grade type which is much thicker.

[JohnMo]

If you need to do more than 3 wraps with your PTFE, your threads do not match.

 

Check everything you have bought is compatible.