Transportation/Hazardous Materials: Pipeline and Hazardous Materials Safety Administration Addresses Question Involving MC 300 Series Cargo Tanks

The United States Department of Transportation Pipeline and Hazardous Materials Safety Administration (“PHMSA”) addressed in a November 26th letter a question addressing the Hazardous Materials Regulations (“HMR”) pressure test requirements for MC 300 series cargo tanks.

PHMSA was responding to a February 4, 2019, email from United Petroleum Transport (“UPT”) of Oklahoma City, Oklahoma.

UPT outlined in its February 4th email the following scenario:

• UPT is the owner of an MC 300 series cargo tank
• In accordance with § 180.405(k), the cargo tank is marked with a MA WP of 3 psig
• Historically, in accordance with §§ 180.405(k) and 180.407(g)(1)(iv), the cargo tank was pressure tested at 3 psig

UPT stated that Table 1 to § 180.407(g)(iv) was amended following the November 7, 2018, publication of the final rule titled:

Hazardous Materials: Response to Petitions from Industry to Modify, Clarify, or Eliminate Regulations

See 83 Fed. Reg. 55792.

PHMSA states that the rulemaking addressed a petition for rulemaking (P-1615) that revised the Table 1 entry for MC 300, 301, 302, 303, 305, and 306 specification cargo tanks to read as:

The test pressure on the name plate or specification plate, or 1.5 times the MAWP, whichever is greater.

The entry was stated to previously read as:

20.7 kPa (3 psig) or design pressure, whichever is greater.

UPT asks whether it was PHMSA’s intention to require a MC 300, 301, 302, 303, 305, or 306 specification cargo tank with a marked MAWP or design pressure of 3 psig to be tested to 4.5 psig (1.5 x MAWP of 3 psig) instead of testing it to 3 psig.

PHMSA answers in the negative, stating in the HM-219A, NPRM, PHMSA had originally proposed to revise § 180.407(g)(1)(iv) to read as:

The test pressure on the name plate or specification plate, 20.7 kPa (3 psig) or design pressure, whichever is greater" [81 FR 42609]. While PHMSA received comments to the proposed amendments in § 180.407(g)(l )(iv), these comments did not request a revision to the pressure specification of “20.7 kPa (3 psig) or design pressure."

PHMSA states that in reviewing the request it identified that the revision was made in error and was not PHMSA’s intention. It is stated to be working to address the error in an upcoming rulemaking. As a result, PHMSA states that UPT can continue to requalify the cargo tank a 3 psig.

A copy of the interpretive letter can be downloaded here.