On July 8, the National Propane Gas Association (NPGA) received formal clarification from the Pipeline and Hazardous Materials Safety Administration (PHMSA) on several key segments of the final rule to extend the hydrostatic pressure test requalification period from five to 10 years for certain types of bobtail delivery trucks. PHMSA clarifications include confirmation that the effective date of the final rule is July 5, 2016. Hydrostatic pressure tests performed on eligible bobtails on and after July 5, 2016 carry a 10-year requalification period; tests performed before July 5, 2016 carry a 5 year requalification period.

The agency also corrected an error in Note 5 of the Table in 180.407(c) that incorrectly indicated test data is necessary for bobtails constructed of NQT SA-612 steel. Only certain bobtails made of NQT SA-202 and NQT SA-455 steel require additional test data for the 10 year requalification period.

Bobtail types that will be eligible for the 10 year requalification are MC-331 cargo tanks that: have water capacity less than 3500 gallons and are used in dedicated propane service; are constructed of NQT SA-612 steel; and/or are constructed of NQT SA-202 or NQT SA-455 steel, provided the materials have full-size equivalent (FSE) Charpy V-notch (CVN) energy test data that demonstrates 75% shear-area ductility at 32°F with an average of three or more samples greater than 15 ft-lb with no sample less than 10 ft-lb.

The association has prepared a fact sheet for bobtail requalification that includes common questions and answers. It is available on NPGA’s website in the Members Only section. It is also preparing a fact sheet related to odorant testing procedures to provide an overview of the final rule on odorant testing requirements. For information, contact Mike Caldarera, vice president of regulatory and technical services at This email address is being protected from spambots. You need JavaScript enabled to view it., or Sarah Reboli, director of regulatory affairs, at This email address is being protected from spambots. You need JavaScript enabled to view it..