Oxygen compatible Gauge

[NetPro]

I picked up a Heise high resolution gauge the other day that I want to use for PP mixing. It has a 4inch face and will register 2000 psi each time around the face. It will go around twice for 4000 PSI. The resolution is 5 PSI and the face is adjustable to set zero - it's a sweet setup.
I thought they typically used stainless steel tubes for high pressures but there is a label on the face that the tube is beryllium copper. I believe it should be O2 compatible but there is also a label on the back "Not for oxygen service". Is this a warning because it was not O2 cleaned during mfg or did I miss something in the O2 compatibility of materials?
It was originally used for GN2 (gaseous nitrogen).

Thanks,
Jeff

 

[ComputerJoe]

I would guess it's there because it reading could be misinterpeted or more likely there's oil in it. A leaky gauge could fuel a disaster.

 

[Akimbo]

All the Heise, and the great majority of gauges I am aware of use beryllium copper Bourdon Tubes, even up to 20,000 PSI. It is very difficult to oxygen clean a Bourdon or Helicoid Tube gauge mechanism without specialized equipment. I would contact Heise
tech support.

Frankly, very few people worry about it for partial pressure mixing. An instrument like the Heise should be panel or wall mounted so the velocity of gas movement at the mechanism is near zero. You could isolate the gauge with an Oxygen compatible fluid column if you want to play it really safe.

 

[Zodiacdiverdave]

A friend of mine came very close to loosing his sight when a gauge blew-up and glass shards were embedded into his face and eyes. My advise is to use that gauge for air and get one you know is going to be compatible for O2.
ZDD

 

[NetPro]

Thanks ZDD
I've been doing some more research on this model of Gauge. It has a cap on the bourdon tube. Per the manual -
"The bleeder also facilitates flushing, cleaning and purging. It is an integral part of the Bourdon tube and is accessible by
removal of the blow out back."
This seems like a good candidate for O2 cleaning and in fact the factory has an O2 cleaning service if you send it in.
Not being one to "send things in", I'll be cleaning it this week.

Netpro

 

[Zodiacdiverdave]

That sounds good, just point the thing away from face the first few times you pressurize it.
ZDD