Jump to content

Filling your divers bottle


Ben Lawrence
 Share

Recommended Posts

When I take my bottle to be filled at Kent diving centre they always put the bottle in a tank of water while filling to keep cool. Speaking to my father in law to day he told me he took his to be filled somewhere an they didn't have a water tank an that the bottle was hot afterwards. Will this do any damage to the bottle or is it even safe filling this way???

Link to comment
Share on other sites

My wife is a cylinder tester, also certified to do divers trimix fills, etc. Her viewpoint was that it is bad practice, which I then typed in.

 

Why is it bad practice ? Her reply : When cylinders are tested, a 'go/no go' gauge is used on the threads that the valve screws into. If you regularly overfill a cylinder, then the threads are likely to expand/deform a little over time, making a fail on the gauge more likely. Meaning that your cylinder is more likely to end up as scrap whgen your test comes around.

She sees this with particular dive groups/clubs which have their own filling gear. Members of one club in particular had a LOT of test failures of this type a couple of years ago, and the only thing they were doing differently was filling to 330 (for 300s) or 250 (for 232s) and allowing to cool. They've now gone back to filling to 300/232, allowing to cool, and then topping up.

 

Out of interest, the shop where she works at they also fill using a cold water bath.

Link to comment
Share on other sites

Most shops dont use a bath any more, due to good old HSE lifting rules and regs.

 

I have been in the dive industry for over 20 years, main users of water baths are abroad where it needs to be in a cooling bath as they are filling huge quantities at once from storage banks, so they can blast the air in. If you are filling straight from the compressor, it is not necessary to do this, unless you are filling a 3 litre from a 25cfm+ compressor.

Best option is fill, and top off if required,

 

Seen plenty of cylinders that have fractured whilst filling, this is down to rust, which can be caused by hot air going into an immersed steel cylinder and condensing, its fine with allly tanks, so just slowly does it, and stay within the pressure of the tanks.

Link to comment
Share on other sites

Would I be correct in assuming, that is the bottle were to fail in the water bath! It would act as a retardant, and take some of the force out of the resulting explosion? Reading up on the effect of firing a bullet into water, I wondered if the same physics weren't applied?

 

Or is it SOLELY for cooling purposes?

Edited by Lord Geordie
Link to comment
Share on other sites

The place I use fills to 300 bar. Cools the cylinder in water if you are waiting for a fill. Allows them to cool whilst filling other cylinders if you are taking advantage of his collect and deliver service. Tops up. Allows to cool and then check fills again!

 

Oh and Lord Geordie, the water would act as a shock absorber.A Hydro test chamber is filled with water before they whack 1.5 x the working pressure in.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...