Moveable Storage Units are large volume compressed gas storage vessels intended for long-term use at facilities which do not have fixed, ASME-type pressure vessels. MSU’s typically have one to nine individual cylinder(s) and provide unregulated nitrogen, helium or breathing air at 6600 psig maximum pressure.

Many KSC MSU’s are covered by DOT-E-9740 which allows for a 10 year hydrostatic re-test interval. This is an expensive operation as the MSU must be disassembled into individual tubes. Fortunately, the Department of Transportation had recently incorporated new Acoustic Emission tests as an approved test method thus eliminating the disassembly requirement. As MSUs come due for their re-test, the more economical acoustic emission tests are being used.