Cylinder gauge

[angrybear]

Has anyone bought a new cyl gauge recently ?
I'm after a replacement, 40mm, 0- 400bar, back entry 1/4 BSPT, can't find one anywhere.

error it's 1/8bspp thread not 1/4bspt

[acmsarh]

If you cannot find the 1/4 bspt one's use an 1/8th bspt one with a 1/4 to 1/8th adaptor.

[ashf9999]

Try ringing SM Gauge in Yate, near Bristol. We use them at work snd can get most things from them. Phone 0117 9654615

[angrybear]

Many thanks,
I just spoke with MDE & it seems my existing gauge is probably not the correct one for their valve to start with

[acmsarh]

I used to work for MDE , If the gauge screws directly into the body of a cylinder valve it should be 1/8th bsptm and if it screws int a t shaped brass/chrome plated block on a separate charging assy then it should be 1/4 bsptm.

[angrybear]

Well now things get interesting, having sent MDE photo's it seems that at some point my gauge has been removed from the valve & a brass sealing ring on the end of the thread has sheared off inside the valve & the gauge was then refitted with PTFE tape to seal it.
Which is why mine appears to have a flat thread base where all the replacements have got a stepped base, All well & good it stopped the leak, but now the gauge needs to be changed the piece sheared off in the valve presents a problem.

Thing is I've never removed the gauge, so it can only have happened at the test/fill centre who probably aren't going to accept responsibility when I go see them on Monday.

It's 1/8 BSPP thread the brass bit in the centre of the valve, should be attached to the bottom of the gauge thread.

[acmsarh]

What you have there in an MDE jubilee valve , The gauge thread has a small pip on the end which has sheared off and there should be a small flat aluminium sealing washer that sit's over that pip and seals in the bottom of the thread and it looks like that is stuck in the bottom of the female thread together with the brass pip, What happens is when the valve is tightened it squashes the alloy washer to seal it air tight but overtighten and the seal is squashed outwards sticking in the hole and the small hole in the centre of the seal is squeezed inwards getting smaller and gripping the brass pip so tight it shears off when removed , If you look at the bottom of the gauge threads you will see a hint of smeared aluminium on the end flat from the alloy seal.