Air Fills

[dyingfly]

Took a 232 12L cylinder to a filling station at a dive site yesterday. Cylinder had the insert for my A-clamp first stage. Came away turned it on and my gauge said 250! - my most generous fill to date being around the 220 mark and the cylinder wasn't really warm either. I thought 232 meant 232 for A clamp for safety reasons- now was the 250 fill a bit naughty in that my head could have been detached from my body-ok or is that I have completely misunderstood about working pressures?

[PeteM]

Convert to DIN then no problems:D

Seriously I would not worry about it. Most gauges over read so you were probably not that much over pressure and there is a margin for error in the design

[Phil Laughton]

Took a 232 12L cylinder to a filling station at a dive site yesterday. Cylinder had the insert for my A-clamp first stage. Came away turned it on and my gauge said 250! - my most generous fill to date being around the 220 mark and the cylinder wasn't really warm either. I thought 232 meant 232 for A clamp for safety reasons- now was the 250 fill a bit naughty in that my head could have been detached from my body-ok or is that I have completely misunderstood about working pressures?

Hi,
If the job is done correctly a cylinder can be safely filled to + 10% of the working pressure, i.e. 232 bar + 10% becomes 255 bar and 300 bar + 10% is 330 bar.
This is an industry wide practice.

Phil

[tony J]

Hi,
If the job is done correctly a cylinder can be safely filled to + 10% of the working pressure, i.e. 232 bar + 10% becomes 255 bar and 300 bar + 10% is 330 bar.
This is an industry wide practice.

Phil
If done safely a cylinder can be filled to (If I remember correctly) +50% over the working pressure. This is what happens during a hydrostatic test. However overfilling will reduce the working life of a cylinder as it will reduce the elasticity. I have no idea about stats on this as if 10% overfilling reduces the life from 2000 fills to 1900, who cares ?. If it reduce it from 2000 to 200, then I would care !

Tony

[Richard Whitcombe]

Well test pressure of a 232 steel is IIRC 348 bar.
The issue isnt the tank itself, its the actual regulator accepting that pressure. Especially the dinosaur a-clamps still so common among club divers in the UK.

[tony J]

Well test pressure of a 232 steel is IIRC 348 bar.
The issue isnt the tank itself, its the actual regulator accepting that pressure. Especially the dinosaur a-clamps still so common among club divers in the UK.
so 50% over fill
but the tank is one issue.
If you fit a 300bar DIN into a 232 bar cyclinder and use with a 300 bar reg and regularly fill your 232 to 300 bar then you will age the cyclinder it more quickly

so "the issue is not the tank itself" should be "the issue can be the tank"

Tony

[ChristianG]

Well test pressure of a 232 steel is IIRC 348 bar.
The issue isnt the tank itself, its the actual regulator accepting that pressure. Especially the dinosaur a-clamps still so common among club divers in the UK.
Amen!

[dyingfly]

Convert to DIN then no problems:D

Seriously I would not worry about it. Most gauges over read so you were probably not that much over pressure and there is a margin for error in the design

I promise to convert to DIN at the next service.

Seriously - on my last trip to the Red Sea the inserts going round were like gold dust and the Allen Keys even more: Had to be the most over-used quote "Who's got the Allen Key?" - prior to one dive we had a temporary misplacement - that really screwed things up.

[ChristianG]

I promise to convert to DIN at the next service.

Seriously - on my last trip to the Red Sea the inserts going round were like gold dust and the Allen Keys even more: Had to be the most over-used quote "Who's got the Allen Key?" - prior to one dive we had a temporary misplacement - that really screwed things up.
There's an answer to that: carry your own - they're (a) not that weighty, (b) not that baggage hungry and (c) you'll only have to worry whether that b@st@rd has given your very own one back to you. There's a case to be made for having your own engraving tool - proves conclusively who owns what and they're cheap as chips. No need to write your name, a simple dimple somewhere innocuous does the job just as well. My allen key has a small drill mark in the end of the short arm. On several occasions I've said words to the effect that there is a mark there, and got it back, sometimes shamefacedly.

I have no problem at all with lending gear, or providing spares, which I usually have a lot of, in fact I'm probably the first one to volunteer, I just get seriously plssed off if it's not returned.

Most people are properly appreciative, the odd extra beer is "appreciative", particularly if it saves a diving holiday, which it has.

[bakerstreet]

I promise to convert to DIN at the next service.

Seriously - on my last trip to the Red Sea the inserts going round were like gold dust and the Allen Keys even more: Had to be the most over-used quote "Who's got the Allen Key?" - prior to one dive we had a temporary misplacement - that really screwed things up.

Cant understand why. Bee using DIN for the last three years. Never had a problem on the red sea boats. In some cases, the allen key was attached to a large bit of rope. Always carry my own allen keys anyway.