Thread info required for the TEMU hydraulic pressure tester

[GreensandsParticipant @greensands]

 

I have recently purchased a hydraulic pressure pipe tester from TEMU to carry out some local boiler leak testing which I gather has been used for this sort of work and is certainly a cheap (and cheerful) tool for the job. The free end of the 1m length of pressure pipe is fitted with what I think is a standard pipe fitting measuring typically 20.5mm O/d but of unknown thread pitch. To be of any use for model engineering purposes a reducing adaptor needs to be made up and screwed onto the existing fitting but before cutting metal I would like to have confirmation of the thread specification and any advice that can be offered which may be of help. All help and assistance much appreciated.

[Andy StopfordParticipant @andystopford50521]

1/2″ BSP – 14 TPI, used the world over for plumbing threads, though quite often with rather loose tolerances.

[bernard towersParticipant @bernardtowers37738]

do you need to make an adaptor ehen you can cut that one off and fit your own?

[GreensandsParticipant @greensands]

Yes, i am coming around to that conclusion myself as the simpler and neater option to an adapter which would  be otherwise too chunky. The ideal arrangement would be to crimp the new fitting to the hose but not having a crimping tool I would probably end up using a suitably sized circlip.

[JasonBModerator @jasonb]

The Temu listing actually says 1/2″ twice which confirms what Andy said.

Hopefully a Jubilee clip rather than a Circlip.

[Andy StopfordParticipant @andystopford50521]

The way I did mine was to buy one of those braided flexi-hoses for connecting kitchen taps with a small (1/8 BSP I think) male thread on one end and a female 1/2 BSP on the other to connect to the test pump. I then made a small adaptor to screw into a convenient bush on the boiler with a 1/8 BSP female thread to attach to the existing hose end.

The advantage of doing this is that the existing hose is short and rather inflexible, and it’s just a real nuisance to attach to the boiler. You can get 500mm long flexis and they make it all much more manageable. And you can still use it for testing your plumbing.

By the way, the pressure gauge on mine was reasonably consistent, but read about 20 psi low.

[JasonBModerator @jasonb]

Do be careful using tap connectors for this. They are often only rated to 10 bar which could easily be exceeded if doing a twice working pressure test on a copper boiler

[Nigel Graham 2Participant @nigelgraham2]

Note those tap-connectors shrouded with braided, very fine stainless-steel wire are not really designed for frequent flexing, contact over edges and so forth, and consequent broken strands are very hard to see but very effective thorns.

How do I know…?

Ouch!

 

(You could add an outer sleeve of non-adhesive heat-shrink sleeving but I’d still heed Jason’s point about their pressure rating first.)

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