The United States Pipeline and Hazardous Materials Safety Administration (“PHMSA”) addressed in a May 31st letter a question regarding clarification of the Hazardous Materials Regulations (“HMR”) applicable to the accident damage protection requirements for certain DOT cargo tank motor vehicles (“CTMVs”) found in 49 C.F.R. § 178.345-8.

The Truck Trailer Manufacturers Association (“TTMA”) asked in a May 11th, 2016 email about:

. . . the requirement for protecting piping, or any device, that if damaged in an accident could result in loss of lading.

The PHMSA letter outlined a series of questions and responses in addressing the query.

First, the agency confirmed that the requirement to provide protection of “piping, or any device, that if damaged in an accident could result in the loss of lading” in § 178.345-8(a)(2) extends to components such as the dust cap, which do not carry lading during transit but could transfer significant forces to areas that do contain lading. Also confirmed was TTMA’s understanding that the 6-inch horizontal set-back design, required as part of the rear-end protection provision in § 178.345-8(d)(1), also applies to:

. . . the dust cap, arms, and hand valves even if these elements do not normally carry lading during transit.

The agency states:

The dust cover and hand valve must be included in the 6-inch horizontal set-back design as they are part of the piping system. However, if the piping includes a stop valve and a sacrificial device such as a shear section, then the piping is considered protected.

PHMSA responds negatively to the final three questions posed by TTMA.

The agency addresses whether the requirement in § 178.345-8(a)(2) concerning protection against loss of lading as mentioned in a prior question applies to other cargo tank piping that is attached but not associated with an outlet valve. It notes that TTMA also asks whether § 178.345-8(a)(2) applies to air or vapor lines installed according to good industry practice (citing TTMA RP 102).

The agency responds in the negative stating:

The provisions in § 178.345-8(a)(2) do not apply to piping that if damaged in an accident could result in a loss of lading from the cargo tank but is not required by the applicable specification.

Finally, in response to whether the 6-inch set back provisions contained in § 178.345-8(d)(1) apply to the air and vapor lines previously mentioned it states:

The answer is no. The rear-end cargo tank protection device requirements contained in § 178.345-8(d)(1) do not apply to piping that if damaged in an accident could result in a loss of lading from the cargo tank but is not required by the applicable specification.

A copy of the letter can be downloaded below.