The National Propane Gas Association announced early July this summer that the hydrostatic pressure test requalification period for select types of bobtail trucks has been extended from 5 to 10 years. The change in policy is the result of a NPGA petition of U.S. Department of Transportation (DOT).
Funding from the Propane Education and Research Council (PERC) allowed the NPGA to engage in lengthy research to support the petition. The research revealed that extending the requalification period results in no loss of safety for particular types of bobtails. The DOT responded to the petition and issued a Final Rule, valid starting on July, 5 2016, extending the requalification period.
The NPGA released a fact sheet detailing the change in policy. They listed two types of bobtails as being qualified for the extended 10 year requalification.
- MC 331 cargo tanks of less than 3,500 gallons water capacity in dedicated propane service constructed of nonquenched and tempered (NQT) SA-612 steel.
- MC 331 cargo tanks of less than 3,500 gallons water capacity in dedicated propane service constructed of NQT SA-202 or NQT SA-455 steels provided the materials for these steels have full-sized equivalent (FSE) Charpy vee notch (CVN) energy test data that demonstrated 75% shear-area ductility at 32 degrees Fahrenheit with an average of 3 or more samples ˃15 ft-lb FSE with no sample ˂10 ft-lb FSE.
Hydrostatic tests that take place on or after July, 5 2016 have a 10 year qualification period. If the tests have taken place before July 5, 2016, the requalification period is still only 5 years.