30 C.F.R. § 18.27 Gaskets.
Title 30 - Mineral Resources
A gasket(s) shall not be used between any two surfaces forming a flame-arresting path except as follows: (a) A gasket of lead, elastomer, or equivalent will be acceptable provided the gasket does not interfere with an acceptable metal-to-metal joint. (b) A lead gasket(s) or equivalent will be acceptable between glass and a hard metal to form all or a part of a flame-arresting path.
Title 30: Mineral Resources
PART 18—ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES
Subpart B—Construction and Design Requirements
§ 18.27 Gaskets.
