Diving tanks and valves

Introduction

Tanks care and cleaning

Recommendations

Valves care and cleaning

Introduction
The tanks are cylindrical containers made of steel (there are also aluminum tanks but these are being used less and less), whose outer surface is zinc coated and painted and which on the inside is coated with an anti corrosion covering.
Its main function is storing air at high pressure (not oxygen, as many believe) which is breathed by the diver on the dive. There are various types of tanks that vary according to pressure and size and other capabilities.
The most commonly used air tanks are those with 8, 10, 12 and 15 liter volumes. The usual charge pressure is 220 atmospheres of pressure, although this can vary. The content gauge is the instrument that allows us to measure the volume of available air.
The tanks are equipped with a special valve that allows for connection of the regulator. There are different types of valves available on the market, the commonest being the DIN valve and the K valve.
The valve is made of various parts:
- The release and shut off valve, which has a screw cap shape and Works by twisting one way or the other.
- Air supply openings the regulator is connected to. Some valves have two of these, thus allowing two regulators to be connected.
- The fixture to the tank. This has a special joint in order to ensure the connection to the tank is perfectly sealed.

Tanks care and cleaning:Given the fact that these tanks contain pressurized air, there are regulations that require the tanks to be checked periodically, every four years by specialists. This inspection is essential in guaranteeing safety during dives.

Recommendations:
1. Verify the date and seal of the last inspection before every dive.
2. Never transport the tanks at their maximum pressure as this can cause overheating which could be dangerous to the person transporting the tanks.
3. Always carry them in a horizontal position preventing them from bumping into each other.
4. Never leave the regulators attached. These must be removed as soon as the dive is over.
5. After washing them down with sweet water, store in the shade in a vertical position with a little air, never totally empty.
6. In order to charge them it is important to take special care not to exceed the tank’s maximum pressure levels. (This is usually 200 atm. of pressure).
7. In order to avoid heating due to the air compression it is advisable to place the tank in a container with cold water during the charge.
8. The tank must be charged gradually .

Valves care and cleaning:The valves form an essential part of the equipment and involve special care:
1. Besides washing them down with plenty of sweet water, it is advisable to apply silicone grease on the join fittings and screws at least once a month.
2. The valve should be able to close easily and should not be shut too tightly as this could damage the pressure seal.
3. Contact between valves should be avoided as a sudden jolt could cause a sudden and violent outburst of air.