Oxygen regulator fault.

[Swampy]

I stripped down the regulator because I thought there was a fault with it.

Now I've reassembled it, I turn on the tank and the line pressure goes up by itself, in about five minutes it gets up to about 60 psi.

The regulator is a Harris 25-100C.

I'm wondering if I've overtightened the front cover and unseated the diaphragm, allowing O2 to go around it, any ideas?


I thought the original fault was the regulator not reading... turns out that Fabrigas issued an empty tank. With the shrink-wrap seal in place, I thought nah, it can't be empty... has to be the regulator not reading... :-P

Now I can't work, any tips appreciated, TIA.

[Swampy]

and and new regulator is $140 with shipping;


HARRIS MODEL 9200 COMPRESSED GAS REGULATOR NIB OXYGEN



This is a two-stage regulator. What's the benefit over a single stage? If it's considerably more expensive, it must be better, right.

[Mecha]

I upgraded to a two stage when my old one shit the bed. It seems to have a lot less fluctuation (almost none) when I kick on the outer oxy. Even when it is really cranked.

[Swampy]

Just thinking it was only a matter of time before upgrading to some better kit anyway.

Thanks for confirming my purchasing decision.

Any ideas how I can bastardise this one to get through?

[Mecha]

I wish I could offer some advice, but I have never worked on the internals of a reg. The most I have done is attach new pressure gauges which is pretty easy.

[Swampy]

Sussed it.

Below is a schematic picture of the oxygen regulator. The adjusting T-handle screws down onto the valve, lifts it from it's eating and allows pressure through to the line.

When I reassembled the regulator, I didn't put enough torque on the 16mm valve body (seen as the item in the centre of the regulator body in the photograph) so tank pressure was seeping past into the line, resulting in line pressure building up whilst the T-handle was screwed all the way out.

I've also put a line of PTFE tape around the valve body thread before tightening down with a 16mm sparkplug socket.

It works a treat now.

So if you ever rebuild your regs for cleaning and your line pressure builds up by itself, this is probably the fault.

[elad65]

The advantage of a two stage regulator (not to be confused with a 2 gauge regulator) is it has two steps in reducing tank pressure. First tank pressure goes into a intermediate pressure regulator dropping to a intermediate pressure quite a bit below tank pressure, second stage of regulation is output stage the user "sets". With intermediate stage regulation the output stage does not have to work against full tank pressure to maintain a smooth more precise pressure balance.

Elad

[Swampy]

Thanks for your excellent clarification.