Changing Pillar Valves

Having just changed all my gear to DIN fitting, I have one cylinder pillar valve that is A Clamp only (no insert). I have a DIN pillar valve and I intend to change them over.
Apart from the obvious point of making sure the cylinder is at atmospheric presure with the valve open, what other points do I need to be aware of? Is it just a matter of just putting a wrench on the valve to undo it, putting in the new valve and torquing it up to a certain point?

All suggestions gratefully received.

Having just changed all my gear to DIN fitting, I have one cylinder pillar valve that is A Clamp only (no insert). I have a DIN pillar valve and I intend to change them over.
Apart from the obvious point of making sure the cylinder is at atmospheric presure with the valve open, what other points do I need to be aware of? Is it just a matter of just putting a wrench on the valve to undo it, putting in the new valve and torquing it up to a certain point?

All suggestions gratefully received.

If you want to do it properly you should:

Comply with EN14189 ? Inspection and maintenance of cylinder valves and EN ISO 13341 ? Fitting valves to cylinders, throughout the process.

Clamp the cylinder in a cylinder vice

Remove the old valve using a pillar valve. To avoid damage to a pillar valve a special clamping tool is required. This is usually manufactured to type. Alternatively, just gash it with a monkey wrench and chuck the damaged valve in the bin.

Clean the cylinder neck thread, remove any grease, foil, tape or corrosion; use a Nylon bristle brush on Al and a wire brush on steel and a cleaning solution where required.

Visually inspect the cylinder threads. If any are not full form or are damaged, burred, exhibit cracks or other imperfections then scrap the cylinder. You might have damaged the threads removing the valve. Don?t risk the life of the filler.

Check the cylinder thread using the appropriate calibrated and in-date thread gauges, both go and no-go gauges are required. Scrap the cylinder if the threads fail the checks.

Undertake an Eddy Current test on the cylinder if Al and made from Al AA6351. You may have stressed the cylinder neck whilst removing the valve so this test would be required.

Check that the cylinder thread and the new valve thread are the same and don?t just look the same and allow the valve to be screwed into the cylinder. There are combinations that are lethal.

Ensure the cylinder neck and valve sealing surfaces are compatible. There are different types. If they are not compatible get a new valve or cylinder to match. You may remember a spat of safety recalls over the last couple of years where manufactures had fitted valves with different sealing surface shapes that were incompatible with the cylinders even though the thread types were OK.

Clean the valve stem thread, removing grease, tape or corrosion. Nylon brush for Al, wire brush for steel and a cleaning solution if required.

Visually inspect the thread.

Gauge the threads using both go and no-go gauges. Scrap the valve if the thread fails.

Fitting the Valve:

Parallel Thread ? ensure that the sealing surfaces are in good condition. Fit a new O ring of the correct size, shape, material and hardness. Do not use PTFE tape with parallel threads.

Taper Thread ? half lap three to five layers of PTFE tape clockwise starting at, and looking from, the small end. PTFE tape must comply with BS 7786.

Screw the valve in hand tight.

Fit the valve installation tool to the valve to enable the application of spanner/torque wrench without damaging the valve.

Tighten the valve to the correct torque. For parallel valves this torque setting is not to prevent gas loss but to ensure the valve does not become loose and to prevent those not considered ?competent persons? by the HSE from removing the valves.

If you are not a ?competent person? you should not do the job but if you do then keep the cylinder away from me once you have.

John

Having just changed all my gear to DIN fitting, I have one cylinder pillar valve that is A Clamp only (no insert). I have a DIN pillar valve and I intend to change them over.
Apart from the obvious point of making sure the cylinder is at atmospheric presure with the valve open, what other points do I need to be aware of? Is it just a matter of just putting a wrench on the valve to undo it, putting in the new valve and torquing it up to a certain point?

All suggestions gratefully received.

When is the test due? Hydo/Visual/O2?

While it's an easy job, I'd live with it until the next test.
You can then get it changed professionally as part of the deal
at no extra cost and more importantly the station can make sure
the new valve is ok as well.

In the meantime, invest in a Din>A-clamp adapter. Might be on
your hols, but sooner or later it will come out of the box.

TerryH

:=Having just changed all my gear to DIN fitting, I have one cylinder pillar valve that is A Clamp only (no insert). I have a DIN pillar valve and I intend to change them over.
:=Apart from the obvious point of making sure the cylinder is at atmospheric presure with the valve open, what other points do I need to be aware of? Is it just a matter of just putting a wrench on the valve to undo it, putting in the new valve and torquing it up to a certain point?
:=
:=All suggestions gratefully received.

When is the test due? Hydo/Visual/O2?

While it's an easy job, I'd live with it until the next test.
You can then get it changed professionally as part of the deal
at no extra cost and more importantly the station can make sure
the new valve is ok as well.

In the meantime, invest in a Din>A-clamp adapter. Might be on
your hols, but sooner or later it will come out of the box.

TerryH

Unfortunately Terry it was tested about 3 months ago, so I don't really want to wait until the next test. As my other two cylinders are DIN it will be a pain to have this one on A clamp

If it was tested so recently, there is a good chance that the shop where you had it serviced won't mind swapping the valves for you. After all, having serviced the cylinder, they know it's ok, and if the din valve is new/ serviced then it isn't going to take them more than 1 minute to do. Always handy to be on good terms with your local tech.
regards
jens

Apart from the obvious point of making sure the cylinder is at atmospheric presure with the valve open,

....about a year ago I helped coordinate a helivac for a (non brit/non bsac) diver who had severed an artery in his groin as a result of using a 'persuader'(HAMMER) to remove a pillar valve. The cylinder travelled some 15 m (through several walls) before settling in a tree. The handle of the spanner caused the injury.

I'm pleased to say he survived. Language/lack of understanding contributed to the above.

(this seemed an appropriate place to post this warning!)

Get it done professionally

The threads may look the same but may actually be different. The thread may look straight but may be tapered. Some cylinders require tapered threads and others straight.

?25 (?16 on e-bay) will get you an A Clamp/DIN adapter or you might even find one of your club members has one. If you are all DIN now you will need to carry an adapter anyway just for that occasion when you suddenly need to borrow a non DIN cylinder.
I am on 300bar DINS and I always have one in case I have a cylinder problem and have to hire /borrow a cylinder on a boat last minute. That way I won't miss my dive

Derek

Having just changed all my gear to DIN fitting, I have one cylinder pillar valve that is A Clamp only (no insert). I have a DIN pillar valve and I intend to change them over.
Apart from the obvious point of making sure the cylinder is at atmospheric pressure with the valve open, what other points do I need to be aware of? Is it just a matter of just putting a wrench on the valve to undo it, putting in the new valve and torquing it up to a certain point?

All suggestions gratefully received.

If it was tested so recently, there is a good chance that the shop where you had it serviced won't mind swapping the valves for you. After all, having serviced the cylinder, they know it's ok, and if the din valve is new/ serviced then it isn't going to take them more than 1 minute to do. Always handy to be on good terms with your local tech.
regards
jens

Unforunately Jens my local shop is PADI and only sees $$$ signs. They don't do 'owt for nowt'

If it was tested so recently, there is a good chance that the shop where you had it serviced won't mind swapping the valves for you. After all, having serviced the cylinder, they know it's ok, and if the din valve is new/ serviced then it isn't going to take them more than 1 minute to do. Always handy to be on good terms with your local tech.
regards
jens

Unforunately Jens my local shop is PADI and only sees $$$ signs. They don't do 'owt for nowt'

If it was tested so recently, there is a good chance that the shop where you had it serviced won't mind swapping the valves for you. After all, having serviced the cylinder, they know it's ok, and if the din valve is new/ serviced then it isn't going to take them more than 1 minute to do. Always handy to be on good terms with your local tech.
regards
jens

Unforunately Jens my local shop is PADI and only sees $$$ signs. They don't do 'owt for nowt'