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The United States Pipeline and Hazardous Materials Safety Administration (“PHMSA”) addressed in a May 7th letter a question regarding the Hazardous Materials Regulations (“HMR”) applicable to certain packaging requirements. See Reference No. 18-0153.
PHMSA was responding to a November 14, 2018, email from FabTech Services, LP (“FabTech”) addressing the transportation of jet perforating guns.
FabTech seeks clarification of the packaging requirements of packing method US 1 from the Table of Packing Methods in § 173.62 of the HMR for jet perforating guns.
The two questions posed include:
- Does US 1 (1)(c) permit the use of end caps that incorporate a metal disk to provide complete metal-to-metal contact, but which are secured with plastic fittings.
PHMSA responds in the affirmative. It states that this provision requires that:
. . . each shaped charge if not completely enclosed in glass or metal, must be fully protected by a metal cover after installation in the gun.
The rationale for the response includes:
- The cover described will give complete metal coverage around the shaped charges, and therefore meeting the requirements (if the plastic fittings are sufficiently robust to prevent loosening of the cover during normal transportation conditions.
- The requirement for a metal cover on the gun (e.g., use of “metal end caps”) is unnecessary where shaped charges within the jet perforating gun system are fully enclosed by metal or glass after installation in the gun.
PHMSA provides an example, noting that:
. . . a shaped charge or “perforator” in a metal case and liner, installed in a metal carrier tube, and then installed in a gun (i.e., steel tube), would not necessitate protection by metal covers provided that the design ensures the shaped charges are fully enclosed in metal (or glass) without the use of such a cap. In this latter example, plastic covers or “end caps” may be suitable for purposes of preventing dust, moisture, or foreign objects from entering the gun body and to protect the ends of the gun body.
- FabTech is also stated to have provided images of an all-metal cover design and asked whether it meets the requirements of US 1 (1)(c).
PHMSA again responds in the affirmative.
The agency states that packing method US 1 (1)(c) requires that:
. . . each shaped charge, if not completely enclosed in the glass or metal, must be fully protected by a metal cover after installation in the gun.
PHMSA concludes that the all-metal cover design meets the requirements of US 1 (1)(c).
A copy of the letter can be downloaded here.
