Cylinder Hydrostatic Testing

Requalification of Cylinders

Once every five (5) years, industrial gas cylinders made of steel are subjected to hydrostatic testing. This is to ensure that the cylinder for use is still able to withstand the working pressure demanded the industry.

For steel alloys such as aluminum, hydrostatic testing is mandated every three (3) years.

Water is the working fluid to be used for pumping pressure inside the cylinder while submerged in a steel container also filled with water.

The cylinder tested will be marked as accepted and safe to use once it has passed the corresponding test criteria. It will be safe to use for another five(5) years(for steel), and another three(3) years for aluminum.

Proper use and handling of cylinders should still be observed after testing.

• Common causes of cylinder failure include:
• Improper handling of cylinder (bumps, falling cylinders, etc.)
• Exposure to hazardous chemical agents
• Rusting (both internal and external)

Cylinders which have incurred internal rusting are most dangerous and may explode at anytime, as the rust is not visible.

For complete technical data, one may refer to #49 Code of Federal Regulations Part 180.209(a).