---
kind: "section"
citation: "30 C.F.R. § 7.99"
title: "30"
number: "7.99"
heading: "Critical characteristics."
url: "https://uscodex.org/cfr/30/7.99"
---

# §7.99. Critical characteristics.


The following critical characteristics shall be inspected or tested on each diesel power package to which an approval marking is affixed:

- (a) **Finish, width, planarity, and clearances of surfaces that form any part of a flame-arresting path.**
- (b) Thickness of walls and flanges that are essential in maintaining the explosion-proof integrity of the diesel power package.
- (c) **Size, spacing, and tightness of fastenings.**
- (d) The means provided to maintain tightness of fastenings.
- (e) Length of thread engagement on fastenings and threaded parts that ensure the explosion-proof integrity of the diesel power package.
- (f) **Diesel engine approval marking.**
- (g) Fuel rate setting to ensure that it is appropriate for the intended application, or a warning tag shall be affixed to the fuel system notifying the purchaser of the need to make proper adjustments.
- (h) Material and dimensions of gaskets that are essential in maintaining the explosion-proof integrity of the diesel power package.
- (i) **Dimensions and assembly of flame arresters.**
- (j) Materials of construction to ensure that the intake system, exhaust system, cooling fans, and belts have been fabricated from the required material.
- (k) **Proper interconnection of the coolant system components and use of specified components.**
- (l) **Proper interconnection of the safety shutdown system components and use of specified components.**
- (m) **All plugs and covers to ensure that they are tightly installed.**
- (n) The inspections and tests described in the diesel power package checklist shall be performed and all requirements shall be met.

## Notes

### Source

Source: 61 FR 55518, Oct. 25, 1996, unless otherwise noted.

### Authority

Authority: 30 U.S.C. 957.

### Source

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