Scuba diving cylinders or scuba diving tanks come in different sizes which can range from about 9" tall by 2" across to a huge 22" tall by 8" in diameter. There are two most common types of scuba diving cylinders. First are those scuba cylinders which are made out of steel and the other which are of aluminum. Scuba diving cylinders play an important role in the lives of the divers. The scuba tanks will allow them to stay under the water for a certain amount of time until the cylinders run out of air. But how do companies ensure the safety of the divers? How do they perform scuba cylinder testing methods?
The Inspectorate for Diving Equipment Servicing and Testing or IDEST suggested the changed standards for scuba cylinder testing. The old BS 5430 steel diving tanks and aluminum cylinders were taken away from the market and were replaced with new standards which are BS EN 1968:2002 for steel gas containers and BS EN 1802:2002 specifically for aluminum gas containers. The new standards were implanted in September 1, 2002.
The inspection date of the scuba dive tanks should also be stamped into the tank in the following order: the year in full followed by the month of testing. It is also compulsory to mark the tank with stickers indicating the next schedule for testing the cylinder.
Professional drivers should now follow the color coding standard of scuba diving cylinders. It is the dive stops and air refilling stations who are expected to insist the color standards of the tanks. This will make sure that only the safe diving cylinders are being filled or refilled.
During the hydraulic cylinder test, the scuba diving cylinder will be filled up with water and then will be put inside a water-filled and a highly pressurized chamber. In the process, the pressure of the water in the air cylinder will then be accelerated to about five thirds of its maximum working pressure and will then cause the cylinder to slowly expand itself. The diving cylinder is said to pass the test if it will be able to pass within the acquired limits of <5%. The tank will not be allowed to be refilled with air if it fails this part of the test. Tanks which pass this stage of scuba cylinder testing will then undergo cleaning and drying. It will again be marked with the current year and month with the initials of the tester or the testing company.
The scuba diving cylinders also have to undergo visual inspections every 2 and a half years. This includes some steps. The first stage is the removal of the tank boot, the bands and the valves and then the inspection of the exterior tank. A device called an endoscope is used in examining the insides of the tank. The tank neck is examined using dental mirrors. The valves are tested to ensure smooth operation when in use.
If in a situation that the scuba tank is determined to be free of damage and corrosion, it will again be reassembled and refilled. The tank will again be stamped with the testing company's ID with the year and the month of inspection. However, if corrosion or any amount of damage is determined, the tank will undergo some series of procedures to treat the flaws. After fixing the damaged scuba diving cylinders, it will again be certified as safe to use by stamping it with the year and month and the facility's ID.