Get your gear ready, part one - cylinders and regulators

Justifying why you should get your gear checked and serviced annually is not difficult. Warranties are usually conditional on your regulator receiving an annual service by an authorised dealer. Manufacturers rely on their dealer network to inform them of issues that can develop with some models, even when they have been well looked after by you. It’s a two-way flow of information that enables a fast response to potential problems that frequently results in service upgrades that are free of charge to you.

The Health and Safety Executive in the UK have reported that in many of the diving accidents that they have investigated, poorly maintained equipment has been a contributory factor. That's hardly surprising when you read internet forum comments such as “I've done 100 dives with it in the last three years and it’s fine”. This is, of course, the well-worn, ‘if it ain’t broke, don’t fix it mentality’. The question is, how often does your regulator have to fail underwater before you decide to get it serviced?

To help you decide whether or not your regulator needs servicing, there are ten very simple checks that you can make yourself without even resorting to opening a toolbox, starting with the first stage:

1. Remove the dust cap and check the condition of the filter. If you can see salt or verdigris, the air flow will be impaired and there will probably be similar corrosion deposits inside the regulator.

2. Check the condition of the hoses. Look for kinks and cracks in the rubber. If the crimped ferrule has a hole in it, you must be able to see the rubber of the hose in the hole. If not then the hose may be pulling out of the ferrule and you are at risk of hose failure.

3. Take a look at the second stage. Gently stretch the mouthpiece and look for holes and tears. Does it look like something that belongs in your mouth? Mouth ulcers would be the least of your problems. To breathe an aerosol of air, water and mould could lead to a serious chest infection.

4. Check the second stage case and front cover for cracks and other damage.

5. Connect the regulator to a full cylinder of air, turn the air on, cup your hand around the mouthpiece and press the purge button a few times and wait. If, after approximately ten to 20 seconds, the second stage starts to leak air, it is an indicator that the first stage is not regulating the pressure to the second stage.

6. Now immerse the whole system in the bath to check for air leaks. Incidentally, Sherwood regulator first stages are supposed to leak and if they don’t, they require servicing. Apart from that unique case, there should be no air bubbles leaking from the system.

7. You can now check the performance of the second stage.Pressing the purge button about 2-3 mm should cause the air to flow. A purge action outside of these limits may be acceptable, depending on the make and model, but the next check will help you to form a conclusion.

8. Shake the water out of the second stage and, while holding the mouthpiece uppermost, slowly immerse the second stage in water until the air just begins to flow. This should occur when the front cover has been immersed by at least 1cm but before water pours into the mouthpiece. This test shouldn’t precipitate a sudden uncontrolled freeflow.

9. If the second stage has a venturi switch, set it to ‘+’ or ‘max’ or ‘dive’, and press the purge button down to cause a freeflow. The freeflow should stop promptly when you cup your hand around the mouthpiece. It should also stop when you turn the switch back to ‘min’.

10. Lastly, turn the air off and purge the system. Before disconnecting the regulator try breathing from the regulator. Does a tight vacuum develop? If you can suck air into the second stage then water will also leak in during the dive.

Moving on to cylinders, have you ever taken the trouble to knock the boot off the bottom of your cylinder? I forgive you if you're thinking “I'd have to be spectacularly bored to want to do that”, but it's one small job that will certainly extend the life of your cylinder and may avoid the additional costs of shot blasting and re-coating. Other checks you should make include:

1. Check the date of manufacture or last test to determine whether or not your cylinder is still in test. (In the UK a test every 2.5 years is a legal requirement).

2. If you use the cylinder for enriched air, check that it is still in oxygen service.

3. Even if your cylinder is in test, an annual internal visual check can help to catch internal corrosion before it becomes too serious.

4. Check the cylinder valve for damage and also smooth and easy operation. Don't wait for a cylinder valve to seize before you get it serviced.

5. Always store a cylinder with clean dry air in it – about 50 bars is sufficient.