Hydrostatic Cylinder Testing Procedures Having your cylinder tested at Frog Dive All diving cylinders in Australia are required to be hydrostatically tested when in use yearly. A hydrostatic test includes: Empty your cylinder of compressed air Inspecting the outside of the cylinder for wear & tear Visually inspecting the cylinder internally for rust and other damage Fill cylinder with water and conduct an expansion/contraction test of the cylinder, then dry. Completing an EDDY current test on aluminium cylinders to discover sustained load cracking (SLC) in the neck thread of the cylinders. Record results of test and issue a test certificate and stamp the cylinder. All Australian Cylinder Test Stations are registered and audited by Standards Australia. All testing is conducted in accordance with relevant Australian Standards. The Standards are: AS 2030.1 1999 - The verification, filling, inspection, testing and maintenance of cylinders for storage and transport of compressed gases AS 2337.1 2004 - Gas cylinder test stations - General requirements, inspection and tests AS 1777 2005 - Aluminium cylinders for compressed gases - seamless Information on Sustained Load Cracking in Aluminium Cylinders For more information regarding sustained load cracking in aluminium cylinders please click here....