What do the numbers on scuba tanks mean?

[Scuba_Nick27]

What would this part mean?
M8303 19/0342/021 (exclude the birth date and transport canada permit) 7694 - 237 ?

 

[Divin'Papaw]

Cold

These are my two latest fills. These tanks have been inside for over a week @ 75 F roughly.

 

[Scuba_Nick27]

These are my two latest fills. These tanks have been inside for over a week @ 75 F roughly.



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Yeah in the Florida heat, any gas expands, so I think if the tanks would cool down to like 70 degrees, your pressure would drop to maybe 3600 - 3700. Are those steel tanks? And what size?

 

[Divin'Papaw]

Yeah in the Florida heat, any gas expands, so I think if the tanks would cool down to like 70 degrees, your pressure would drop to maybe 3600 - 3700. Are those steel tanks? And what size?

Worthington HP100s. At the shop I use they use a water bath and fill them slowly and allow me to wait for a final top off. In about 30 minutes I leave with cold fills to 3700-3900 roughly as you see with these tanks. That gives me 110-113 cf of EAN36 in my HP100s. I love the shop!!

It helps that I also go on a weekday mid-morning just before lunch, typically Mon or Tue. The banks are full and the shop isn't busy. Plenty of time and gas in the banks to get nice fills.

 

[broncobowsher]

These are my two latest fills. These tanks have been inside for over a week @ 75 F roughly.



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In Florida that is common. Outside Florida, not common.

 

[Scared Silly]

That makes some sense ... except for where does 3442 come from? I always wondered that. Seems so random.

Because at 3500psi the valve is required to be 7 threads (7/8" 300 bar) only instead of 5 threads (3/4" 200 bar) or yoke.

What would this part mean?
M8303 19/0342/021 (exclude the birth date and transport canada permit) 7694 - 237 ?

M8303 is the mfg id for Faber

19 year made 2019
0342 Batch number
021 Sequence in batch - e.g. 21th cylinder in the batch

TC-SU 7694 (TC == Transport Canada / SU 7694 == Special Use Number)
237 (working pressure in bar)

 

[Divin'Papaw]

In Florida that is common. Outside Florida, not common.

Reason #15 for why I'm glad I moved to FL. But keep in mind that I'm not in "Cave Country". This is Southeast FL ... Palm Beach County.

But you are correct. Back in the Midwest I was very lucky to get a fill that cooled to maybe 3400. That was a GOOD FILL.

 

[Scuba_Nick27]

And that's called using physics in real life. Aah, the good 'ol Boyle and Ideal Gas Laws!

 

[Scuba_Nick27]

Because at 3500psi the valve is required to be 7 threads (300 bar) only instead of 5 threads (200 bar) or yoke.



M8303 is the mfg id for Faber

19 year made 2019
0342 Batch number
021 Sequence in batch - e.g. 21th cylinder in the batch

TC-SU 7694 (TC == Transport Canada / SU 7694 == Special Use Number)
237 (working pressure in bar)

That is cool. 342nd batch, 21st cylinder in the batch.

 

[NorCalDM]

PSI-PCI - Filling Cylinders In Water - Time to Review
Here is a link to a PSI article about water baths and overfilling cylinders. This issue has been around for awhile. I'm not leaning one way or the other people can do what they want with there personal cylinders and I'm one for a good fill. My personal thought and this is based on the industry I'm in is all metal fatigues and by continually pressurizing a cylinder above it's design pressure you are shortening its life span as fatigue does not go away you only add to it but by how much does it shorten it? you only know when it lets go.