PHMSA letter of interpretation

Accumulators Assembled in Machinery and Not Assembled in Machinery

Pipeline and Hazardous Materials Safety Administration · Dec 17, 1999 · Reference No. 99-0318

PHMSA says to use caution with this letter. On January 21st, 2016, PHMSA published Final Rule, HM-233F, which incorporated Special Permit 8786 by revising § 173.306(f) to provide an alternate test procedure for hydraulic accumulators.

Interprets: 49 CFR § 173.306(f)

This is in response to your letter dated November 19, 1999, requesting clarification regarding the applicability of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) to the transportation of accumulators. Specifically, you ask if the HMR apply to replacement accumulators not assembled in machinery and accumulators transported in assembled machinery.

As provided by § 173.306(f)(1), accumulators which are installed in assembled machinery and constructed with a burst pressure of at least five times their charged pressure at 701F are not subject to the HMR. Accumulators, as described in § 173.306(f), not in assembled machinery are subject to the HMR. However, accumulators intended to function as shock absorbers, struts, gas spring, pneumatic springs or other impact or energy-absorbing devices are not subject to the HMR provided they meet the criteria specified in § 173.306(f)(4).

A letter of interpretation applies the regulations to the facts the requester described. It isn’t a regulation and isn’t legal advice. The agency’s copy.