Sealing G1/4 pressure gauge into water pressure regulator

[Tim S]

Hi,

Got one of these to fit tomorrow:

noticed that the gauge (supplied loose) has a G1/4 (therefore parallel BSP) male thread, an dthe valve body has the corresponding femail thread.

The guage is flat bottomed, same with seat in valve.

No washers have been supplied, except a little o-ring built into a spare platic sealing plug that can be fitted instead of the guage.

What should I do: buy a suitably sized o-ring, use a fibre washer or a little bit of potable water sealing gunk on the end (which worries me as it may block the guage port)?

I'm a bit thick when it comes to "iron" type joints...

Ta

Tim

[Andrew Gabriel]

I don't know that it's "right", but I would use ptfe tape, many turns so it's a tight fit (might take a couple of attempts to guess the right number).

You can't have that sort of fitting seal by bottoming out, as it will probably do that with the guage facing the wall (unless the guage freely rotates on its male fitting).

[Tim S]

Andrew Gabriel coughed up some electrons that declared:

Thanks Andrew.

I'd mentally discounted PTFE as it was a parallel thread - but you are right, the guage needs to end up in a known poistion.

Perhaps in the light of what you said, maybe some Threadseal XS would also be an option?

I'll try it first with both gas and "normal" PTFE tape and see how it feels...

Cheers

Tim

[YAPH]

Definitely the loctite thread sealing thread

[Tim S]

YAPH coughed up some electrons that declared:

Is the Loctite version WRAS approved? Their website seems curiously quiet on the subject...

BTW John - did you mean Loctite rather than Rocol or Loctite rather than PTFE tape?

Cheers

Tim

[Tim S]

Andrew Gabriel coughed up some electrons that declared:

About 8 turns of gas PTFE. Glad I didn't start with water grade!

Nice tight fit now. Have yet to test for water tightness.

I did try an o-ring in the bottom. It was hard to tell if it had hit the ring or not. tried 2 o-rings, could tell now. But that seemed like an unstable crap idea. Took them out and went over to PTFE. Very weird it's not a taper fit. That could easily be adjusted for position with a turn or two less of PTFE. And you'd know it was a basically correct assembly...

A suitably thick fibre washer + Boss Universal or a soft copper washer might also do it, but with the latter I'd be into the "emerying washer down" territory like it used to be with castellated wheel bearing nuts!

Cheers

Tim

[Tim S]

Tim S coughed up some electrons that declared:

Bing?

:)

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Tim S saying something like:

You were doing it wrong, then.

[Tim S]

Grimly Curmudgeon coughed up some electrons that declared:

How should you do it?

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Tim S saying something like:

For taper bearings: take the play out then back to the first available split pin hole. Millions of them done like that, but if you really want to be anal, you could torque it.

For ball races with a spacer between: apply the proper torque and you'll find the castellated cap or other device will fit one of the holes in some position. Sometimes it's permissable to tighten or slacken it slightly to enable this. Usually it gets done that way anyhow.

[Tim S]

Tim S coughed up some electrons that declared:

Yep, about 8 turns gas PTFE did the trick. It's running and not a hint of a leak.

Water grade PTFE would have taken a lot more - think I did the right thing...

[dennis]

Isn't eight turns of gas PTFE thicker than the thread? What's holding it in?

[Tim S]

dennis@home coughed up some electrons that declared:

The thread cut through. I know this because I backed it out after the first

3-4 turns to have a look. The PTFE had bedded down in the grooves quite nicely.

Given how sloppy it was I really didn't want any less tape.

Can't imagine why they didn't use a taper thread...

Cheers

Tim