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SCUBA Cylinder Hydro- Testing in Thailand and Southeast Asia


RIN Locator

The Cylinder Requalification Locator at allows you to search for an approved cylinder requalifier. By entering a city/state or zip code or "Thailand" , this tool will provide a list of approved cylinder requalifiers including address, contact information, and the authorized testing methods and cylinder specifications for the approved entity.

If you love to go SCUBA diving off the coast of Thailand, you know how important your self-contained underwater breathing apparatus (SCUBA) is. That’s why you made a careful selection when you picked out the tank a few years ago.


Of course, purchasing a quality SCUBA tank is only the first step. Then, you must have the cylinder hydrostatically ( HST) or hydro-tested in accordance with Department of Transportation (DOT) of USA requirements. If it’s time for your next hydro-test, look to Aerospace MRO for the services you need. Our facility is equipped to hydrostatically test various types of pressurized cylinders, including SCUBA tanks under DOT Approval.



A hydro-test is the method used to validate the structural integrity and safety of a high-pressure cylinder, such as a fire extinguisher. SCUBA tanks are also tested in this manner because hydro-testing meets all of the DOT’s requirements for pressure test performance. Without routine testing, a degraded SCUBA tank could rupture and endanger the user’s life.


There are different ways perform SCUBA cylinder hydro-testing, but at Aerospace MRO, we stick to the standard water jacket method. Here’s what this process entails:


• Empty the contents of the cylinder and perform a visual inspection of the interior and exterior, looking for pitting, corrosion, and other problems that could cause the tank to fail the test before it has even begun.

• If the cylinder passes the visual inspection, place it inside a steel test chamber and fill the chamber with water.

• Fill the canister with water and pressurize it to about 150% of the designated pressure limit.

• Hold the pressure for the required amount of time and examine the pressurized cylinder for signs of poor structural integrity, including leaks and changes in shape.

• Depressurize the cylinder, and as long as it passes the test, recharge it and return it to the customer, ready to be used in the next diving expedition.




The DOT requires hydrostatic tests for SCUBA tanks every 5 years. If you’re not sure when the last test was performed, check the outside of the cylinder. There, you’ll find the year of manufacture, which is your first hint. If this date was about five years ago, it’s time for the cylinder’s first hydro-test.


If the date of manufacture was well over 5 years ago, look for a record of previous tests, which should be permanently marked on the outside of the cylinder. If you see no previous test dates, bring your SCUBA tank to Aerospace MRO to bring the cylinder up to code.


Before you refill the tank, make sure you check the re-test date. If 5 years have elapsed, have a hydro-test performed first. This is for your safety, peace of mind, and code compliance.




To take advantage of DOT-approved hydrostatic testing techniques in Thailand and Southeast Asia, look no further than Aerospace MRO. We can perform the services you need quickly and thoroughly so you can go on your next dive with complete confidence.


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