The visual test should be performed once a year by a Certified Inspector and is to review the external and internal condition of the tank to certify that the tank is clean, dry and free of rust.
Internally a tank in good condition should not have cracks , corrosion or moisture, so the inspector remove the valve completely empty tank and with a special light diagnosed the state of the inside of the tank . If the practice internal visual inspection , a tank has rust inside it should be cleaned with abrasive material.
Externally it should not be beaten , repainted heat , or have cracks , dents or bulges .
It must also check that the valve is free of corrosion.
If the tank approves the review, the inspector will place a sticker on the tank approving the safe use of this , plus the customer will be given a report signed by the inspector.
The hydrostatic test should be performed every 5 years by a certified inspector and is done to check the strength and flexibility of the walls of the cylinders.
This test is to withdraw the valve, fill the tank with water and place in a water jacket which is sealed to subdue the tank at a pressure of 5/3 of their working capacity by 30 seconds. The tank will expand while subjected to high pressure, such as pressure is removed the tank back to its original volume.
A cylinder passes the hydrostatic test when the final volume of the tank is less than 10% of the maximum volume expanded, but if the volume is greater, the tank will be drilled as a security measure, as it has lost the ability to receive the air resisting pressure.
This procedure is performed in a water jacket because it is much safer because the water in case of explosion, dissipate the energy produced.
If the tank approves the revision the tank shall be marked with the date of approval, also be given the customer a report signed by the inspector.
It is important to note that if the tank does not have the mark indicating that it is up with the hydrostatic test, will not be charged any dive shop or workshops cargo.
Sport diving tanks are loaded with pure , dry, filtered compressed air.
It is not acceptable compressors fill them with bad or no filters for carbon monoxide present in the surface could enter the tank causing poisoning while diving . Water World guarantees pure air in their tanks.
When a tank corrosion is dirty it must be cleaned to avoid contaminating the air flowing inside.
Internal cleaning involves washing with special chemicals to remove any debris that the tank may have.