Northeast Pressure Vessel Testing Ultrasonic Testing

Cylinders passing retest are marked with our requalification number (RIN) D500 and retest date, immediately after successful completion.

For each cylinder tested, a report is generated and includes all pertinent data identifying the cylinder, cylinder owner, DOT specification, test criteria, and result, all in accordance with 49 CFR.

Our facility in Westborough, MA has a double jacket system capable of handling two compressed gas cylinders at the same time; thus, allowing NEPVT to shorten the time it takes to requalify your cylinders.

NEPVT performs requalification of compressed gas cylinders using hydrostatic testing. This method consists of enclosing a cylinder filled with water inside a test jackets filled with water. Pressure is then applied internally to the cylinder, causing the cylinder to expand. The total and permanent volumetric expansions of the cylinder are recorded by measuring the amount of water displaced by the expansion of the cylinder under pressure and after the pressure has been released. After the cylinder is tested, proper drying methods are employed to ensure all traces of moisture have been removed.

Water Jacket Test Method

In accordance with regulations specified in the United Stated by the U.S. Department of Transportation (DOT) certain compressed gas cylinders must be periodically requalified and certified safe for use.

Northeast Pressure Vessel Testing (NEPVT) has trained, experienced technicians to perform evaluations to assess your cylinder’s integrity, in accordance with DOT and CGA guidelines and specifications.