low pressure, medium pressure, high pressure cylinders and valves for each

[sandanbob]

Hi!

I thought I had read (not sure where, at the moment) that 3500 psi was the cut off, at and above which cylinders become "high pressure", and require a DIN type valve.

I believe I have seen tanks marketed at 34XX psi with yoke valves, perhaps as 'medium pressure'?

And, there are low pressure tanks, such as certain steel tanks, that typically would have a yoke valve (in my limited experience.)

Can someone confirm for me where 'high pressure' begins, and if that is the cutoff from yoke to DIN valves? Is there an actual mid/medium pressure category?

Thanks, and have a great weekend!

Bob

 

[runsongas]

3500 psi tanks all require a 300 bar din valve and 7/8 UNF neck per DOT regs. anything with a lower service pressure including 3442 psi exemption tanks and the 3AA 3180 psi tanks (3498 with 10% overfill) will take convertible 3/4 nps neck valves outside of some vintage low pressure tanks that had 1/2 NPT necks

 

[Tracy]

3500 psi tanks all require a 300 bar din valve and 7/8 UNF neck per DOT regs. anything with a lower service pressure including 3442 psi exemption tanks and the 3AA 3180 psi tanks (3498 with 10% overfill) will take convertible 3/4 nps neck valves outside of some vintage low pressure tanks that had 1/2 NPT necks

What DOT regs state that?

 

[runsongas]

iso 12209:2013 standard for Gas cylinder outlet connections which is applied by the DOT. 3500 psi exceeds the temperature corrected limit of 232 bar@15C for yoke.

 

[rhwestfall]

Adding to this, modern yoke can be used on 3442 psi cylinders filled to rated capacity.

 

[happy-diver]

What's your new avatar runsongas, a sunken alien traversing device?

 

[runsongas]

air compressor from the fujikawa maru nicknamed r2d2

 

[sandanbob]

Speaking of valves- are there valve covers that fit the pro/converter valves? The standard ones seem to be quite tight.

 

[Gone for diving]

Always wondered why 3442 psi cylinders weren't rounded up.... kinda makes sense.

 

[Bob DBF]

..outside of some vintage low pressure tanks that had 1/2 NPT necks

Don't forget the even rarer 1/2 NPS, before the 3/4 NPS became the standard.

Adding to this, modern yoke can be used on 3442 psi cylinders filled to rated capacity.

Or on the Faber MP at 3498 psi, sometimes more with a good fill.

A yoke fitting can be made for any pressure as a din, it will not be as elagant a solution but it will work. I have a Sherwood yoke made for 4000# service, made back in the early '80's, looking foward to higher pressure tanks, before DIN was a thing.