The National Propane Gas Association (NPGA) received formal clarification on July 8, 2016 from the Pipeline & Hazardous Materials Safety Administration (PHMSA) regarding several key aspects of the final rule to extend the hydrostatic pressure test requalification period from 5 to 10 years for certain types of bobtails. The formal letter from PHMSA is a valid correction to the final rule until PHMSA publishes the correction in the Code of Federal Regulations. PHMSA communicated the corrections to the Federal Motor Carrier Safety Administration (FMCSA), as well.
Bobtail MC331 JarcoPolar 2016
Clarifications from PHMSA include 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. Pressure tests performed before July 5, 2016 still carry a 5 year requalification period.

PHMSA 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 to be eligible for the 10 year requalification period.

The types of bobtails that are eligible for the 10 year requalification period are MC 331 cargo tanks:
• With water capacity less than 3,500 gallons and used in dedicated propane service;
• Constructed of NQT SA-612 steel; and/or
• Constructed of NQT SA-202 or NQT SA-455 steels, provided the materials for these steels have full-size 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 ˃ 15ft-lb FSE with no
sample ˂ 10ft-lb.

NPGA offers a fact sheet for Bobtail Requalification that includes Common Questions & Answers, which is available in the "Members" section of NPGA's website. Please contact Mike Caldarera, NPGA Vice President of Regulatory & Technical Services, or Sarah Reboli, Director of Regulatory Affairs, with any questions or comments.