§7.305. Critical characteristics.

30 C.F.R. § 7.305

The following critical characteristics shall be inspected on each motor assembly to which an approval marking is affixed:

(a)

Finish, width, and planarity of surfaces that form any part of a flame-arresting path.

(b)

Clearances between mating parts that form flame-arresting paths.

(c)

Thickness of walls, flanges, and covers that are essential in maintaining the explosion-proof integrity of the enclosure.

(d)

Spacing of fastenings.

(e)

Length of thread engagement on fastenings and threaded parts that assure the explosion-proof integrity of the enclosure.

(f)

Use of lockwasher or equivalent with all fastenings.

(g)

Dimensions which affect compliance with the requirements for packing gland parts in § 7.304 of this part.

Notes, amendments, and revision history

Source: 57 FR 61193, Dec. 23, 1992, unless otherwise noted.

Authority: 30 U.S.C. 957.

Source: 53 FR 23500, June 22, 1988, unless otherwise noted.