Cylinder & Valve Preparation and Care
A scuba cylinder is your life line under the water, without it you would not be able to enjoy scuba diving at its best; because it takes care of you, it is important that you take care of it. With the proper handling and maintenance, your cylinder and valve can last you many years and see you through thousands of dives. Here we talk you through the basic steps of caring for your cylinder.
As your cylinder will come with the valve already installed, so there isn't a great deal of preparation required with your dive cylinder. Aside from assembling it with the rest of your scuba gear, the only preparation you need to do is have it filled at a reputable fill station. We offer tank refills here at Deep Blue, click here for more information.
Out of the water, you have to be very careful with your scuba cylinder. They are heavy, expensive and need to be handled with care to ensure they aren't damaged beyond use. This is difficult as the cylindrical shape tends to roll when lying down, and they are unstable left standing. The cylindrical shape provides an important purpose though, which is why it is the only design on the market; it is structurally very strong for containing the high pressured air. One dint could damage the integral structure and render your cylinder useless so to avoid this happening, always block or secure them so they can't fall or roll.
Don't leave your cylinder standing unattended because they fall over easily; this may not just damage the cylinder itself but other important piece of equipment such as your BCD or regulator if your unit was set up. If for whatever reason you do need to leave your cylinder stood up, say to save space on a boat or in storage, you need to secure them well so that there is no possibility of them toppling. Dive boats often have special racks for this exact purpose. When transporting your cylinder by car, lay them down horizontally and block them in with other soft items of equipment or better yet, tie them down.
Valves should open easily and smoothly. If there's any difficulty in operation, don't try to lubricate the valve yourself but take it to your nearest dive centre to be looked at. We here at Deep Blue Dive offer cylinder and valve replacements and repairs, click here for more information. Closing a valve too tightly can damage its high pressure seal. When in use, make sure you open and close the valve slowly and gently to avoid over tightening and possible rupturing. With old style valves, it is common to turn the valve all the way and then a quarter of a turn back, so that the mechanism does not become stiff however this is unnecessary with many modern models.
Rinsing your cylinder and valves in fresh water after every dive is a good habit to get into; especially if you have been diving in the sea as salt water corrosion can take its toll after time.
It is also very important to store your cylinder out of direct sunlight. Whilst excessive sunlight and heat can damage almost all dive gear, it is particularly imperative when it comes to your cylinder, as excessive heat can cause the pressure of compressed air to rise when exposed for a prolonged duration of time. Full scuba cylinders left in a hot environment, for example, can rupture the valve's burst discs, especially when full.
Store your cylinder in a cool place with 10-20 bar of air in it; this will help to keep moisture out of it and prevent damage from the inside. Also, we recommend that if you store a cylinder without using it before longer than six months, have the cylinder refilled as the air inside can become stale.
Keeping dry and checking for Corrossion
Your dive operator will fill your cylinder with totally dry air because moisture inside can cause rust or corrosion on its inner surface. The best way for you to keep water completely out of your cylinder is to never let it run completely empty. If you do allow this to happen, close the valve immediately to keep moisture out. Water can enter an empty cylinder by backing up through a regulator so having the regulator attached doesn't guarantee a dry interior. Also, bleeding the air from your cylinder quickly can cause internal condensation and corrosion.
In recreational diving, scuba cylinders should only be filled with compressed air for breathing NEVER pure oxygen. Your tank should only be filled to the rated pressure since overfilling can lead to metal fatigue and weaken the structure of your cylinder, thus shortening its lifespan.
Because cylinders are subject to metal fatigue, even when used correctly, they must receive periodic pressure tests called hydrostatic tests. The test subjects the cylinder to high pressure in a special testing tank to see how much it expands and contracts and therefore judge the metal fatigue or stress. When passed, the tester will stamp the test date onto it. You need this stamp as professional dive centres will not refill your tanks with air unless it has passed a current hydrostatic test. How often you need to have your tank tested is subject to regulations set out by your country and can vary from 2 to 5 years.
Your cylinder may have a rubber or plastic boot, which allows the cylinder to stand (where appropriate) and creates some protection against bumps and scratches. Check periodically under the boot of your cylinder for rust or corrosion although internal corrosion will need to be looked for by a professional at least once a year.