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Hydrostatic Testing

Hydrostatic Testing​

Hawaiian Diving Adventures

Specific federal requirements and manufacturer guidelines govern hydrostatic testing of high-pressure cylinders. All compressed gas cylinders must undergo hydrostatic testing every five years. This is mandated by the DOT (Department of Transportation) and PHMSA (Pipeline and Hazardous Materials Safety Administration), the government agencies that regulate compressed gas cylinders used for SCUBA and SCBA.
We will not fill any tank without a stamp indicating a hydrostatic test within the past five years, or if we suspect the cylinder to be unsafe to fill.
Please contact us to arrange cylinder drop-off for service 808-232-3193.

In-House Testing

Hawaiian Diving Adventures is the only dive shop on Oahu that has a hydro station at our facility. We are trained and certified to perform this testing, which means you get to talk to the actual technicians who tested your cylinder and can answer your questions. We follow PSI/PCI as well as SDI/TDI standards of hydrostatic testing and visual inspections, as mandated by the DOT and PHMSA.

Save Time & Money

Many other dive shops bring us their tanks for testing. Some people actually send their cylinders off-island, at additional time and expense. Shipping off-island also requires a local VIP, because shipping the cylinders requires they be empty with valves removed. If you are on Oahu, bring us your tanks to save some money and get your tanks back into service sooner!

Complimentary VIP & Air Fill

Federal law requires that all hydrostatic testing includes a Visual Inspection (VIP). We do not charge extra for a VIP at the time of a hydro, and we even include a complimentary air fill! If your tank has a current hydro stamp, but simply needs an annual VIP, please check out our VIP cylinder inspections page.


Hydrostatic inspection is $45. 
This includes stamping the cylinder with the hydrostatic test date, as well as a Visual Inspection with updated VIP sticker and an air fill.

Service Time

We typically complete hydrostatic inspections within two weeks, although our schedule can vary by season and demand. On the day you drop off your cylinder, we can let you know approximately when your cylinder will be available for pickup. We will call you on the day it is ready, and advise you of any issues we may have discovered.

Valve Rebuilds

Many divers neglect their tank valves and don’t service them until there is a problem. We recommend servicing your tank valve with each Hydrostatic Test (“hydro”). If your cylinder valve was not serviced with your latest hydro, or you do not know if it was, we can easily perform this service during a VIP. Some older valves do not have o-rings, or if you have an older valve with o-rings, we recommend upgrading to the newer kits that use Teflon washers instead of o-rings. Tank valve services and prices depend on your type of cylinder valve and its condition.

Eddy-Current Testing

We use Eddy-Current testing (also known as “eddy testing” or ECT) to detect sustained-load cracking (SLC) in aluminum alloy cylinders. All aluminum alloy 6351-T6 tanks require Eddy-Current Testing at least every five years. However, all aluminum SCUBA and SCBA cylinders manufactured after 1990 do not use aluminum alloy 6351-T6. We generally recommend annual Eddy-Testing for all aluminum alloy 6351-T6 tanks. Steel tanks or tanks made from aluminum alloy 6061 do not require Eddy Testing.

At this time, we no longer do Eddy-Current Testing