What and how is it used ?

[dead dog]

I saw this on eBay tonight and can't make any idea what it is and how it works. I couldn't see any releas valve on it. Why would need two gauges on this vale ?

Vintage US Scuba Divers Aqua Lung Compressed Air Gage PSI Gage 0 3000 | eBay


Bill
dead dog

 

[socaljohn]

I noticed the red inner scale on the side ways gage then found this
OXYGEN CYLINDERS. -A typical oxygen cylinder (fig. 15-24) is made of steel and has a capacity of 220 cubic feet at a pressure of 2,000 psi and a temperature of 70°F. Each oxygen cylinder has a high-pressure outlet valve located at the top of the cylinder, a removable metal cap for the protection of the outlet valve during shipment or storage, and a low melting point safety fuse plug and disk. All oxygen cylinders are painted green for identification. Technical oxygen cylinders are solid green, while breathing oxygen cylinders are green with a white band around the top.
So I guess it might have been used for to check the pressure in a welding tank though why the aqualung gage was also needed I cannot imagine. Maybe someone else can take this further.

 

[Luis H]

That yoke fitting is the standard O2 fitting (with the index pins) for the portable EMS type of O2 cylinder. It is not what you would normally find in the large storage type of cylinder (220 cubic feet, etc.).

Someone put this together, but I can't figure out the purpose of the two gauges. I also don't see a good way of bleeding the pressure.

 

[John C. Ratliff]

Luis, I agree that it looks pretty weird. Perhaps the two gauges were used as a check against each other. These gauges were never real accurate. But you raise a good point--how to bleed off the pressure. If used on an oxygen cylinder, I'd be very wary as trying to undo the seal by simply twisting the gauge to bleed off pressure could lead to an oxygen fire/explosion.

SeaRat

 

[Nwcid]

If used on an oxygen cylinder, I'd be very wary as trying to undo the seal by simply twisting the gauge to bleed off pressure could lead to an oxygen fire/explosion.

SeaRat

Interesting comment and a good point.

We cascade fill our own portable O2 tanks at work. We probably fill an average of 5 tanks/day, and I have worked there over 11 years now. There is no bleeder valve in our system, we just turn off both valves (cascade and tank) then loosen the yoke fitting to bleed off pressure. Nothing crazy has happened yet.

I know this is probably not the safest practice (I leaned this in the past year as I have started reading about at home gas blending) but it is not as scary as it is made out to be either. When I started reading the O2 Hackers guild I would have been scared to even work with O2 had I not done it for so long. O2 Hacker states filling at 60psi/min yet I have seen MANY folks fill tanks almost as fast as they will fill. When I was "taught" I was told to fill slow but even then it was still probably 500+psi/min.

 

[rhwestfall]

There are two because the individual could not find a "double female" union, and resorted to a "tee" (or didn't have a plug handy). Its all scabbed together stuff.....

you should see some of the stuff I got from "an estate of a diver"..... what was this for????

 

[dead dog]

Both gauges will read the same, how does that help ?

 

[rhwestfall]

Both gauges will read the same, how does that help ?

maybe....

 

[Luis H]

There are two because the individual could not find a "double female" union, and resorted to a "tee" (or didn't have a plug handy). Its all scabbed together stuff.....

I agree.

---------- Post added August 8th, 2013 at 11:06 PM ----------

Interesting comment and a good point.

We cascade fill our own portable O2 tanks at work. We probably fill an average of 5 tanks/day, and I have worked there over 11 years now. There is no bleeder valve in our system, we just turn off both valves (cascade and tank) then loosen the yoke fitting to bleed off pressure. Nothing crazy has happened yet.

I know this is probably not the safest practice (I leaned this in the past year as I have started reading about at home gas blending) but it is not as scary as it is made out to be either. When I started reading the O2 Hackers guild I would have been scared to even work with O2 had I not done it for so long. O2 Hacker states filling at 60psi/min yet I have seen MANY folks fill tanks almost as fast as they will fill. When I was "taught" I was told to fill slow but even then it was still probably 500+psi/min.

The O2 yoke connection shown was used for many years (actually decades) with a plastic washer to seal between the tank valve and the yoke fitting (or O2 regulator). I don't see much of a problem bleeding the O2 pressure with that plastic washer.

In the last few years the plastic washer has been replaced with an O-ring that is captured in the inside diameter of a brass washer. The brass washer keeps the O-ring from extruding since the fitting was not designed with an O-ring groove. With this new arrangement, I do see a problem bleeding the pressure by just loosening the yoke. I think that you may extrude some O-rings and the bleeding rate will not be very predictable.

If you are connecting with a CGA-540 brass O2 fitting to a large storage cylinder at the other end, I would probably use that end to bleed the gas pressure.

 

[captain]

There are two because the individual could not find a "double female" union, and resorted to a "tee" (or didn't have a plug handy). Its all scabbed together stuff.....

you should see some of the stuff I got from "an estate of a diver"..... what was this for????

Looks like it could be for surface supplied air source with two possibilities. ! Surface supply hose on one port and a gauge on the other or 2, surface supply on one port and a second source of air from a bailout cylinder and first stage on the other port.