---
kind: "section"
citation: "30 C.F.R. § 7.104"
title: "30"
number: "7.104"
heading: "Internal static pressure test."
url: "https://uscodex.org/cfr/30/7.104"
---

# §7.104. Internal static pressure test.

- (a) **Test procedures.**
  - (1) **Isolate and seal each segment of the intake system or exhaust system to allow pressurization.**
  - (2) Internally pressurize each segment of the intake system or exhaust system to four times the maximum pressure observed in each segment during the tests of § [7.100](/cfr/30/7.100.md), or [150](/cfr/30/150.md) psig ±5 psig, whichever is less. Maintain the pressure for a minimum of 10 seconds.
  - (3) Following the pressure hold, the pressure shall be removed and the pressurizing agent removed from the intake system or exhaust system.
- (b) **Acceptable performance.**
  - (1) The intake system or exhaust system, during pressurization, shall not exhibit—
    - (i) Leakage through welds and gasketed joints; or
    - (ii) Leakage other than along joints meeting the explosion-proof requirements of [§ 7.98(q)](/cfr/30/7.98.md?p=q).
  - (2) Following removal of the pressurizing agent, the intake system or exhaust system shall not exhibit any—
    - (i) Changes in fastening torque;
    - (ii) Visible cracks in welds;
    - (iii) Permanent deformation affecting the length or gap of any flame-arresting paths;
    - (iv) Stretched or bent fastenings;
    - (v) Damaged threads of parts affecting the explosion-proof integrity of the intake system or exhaust system; or
    - (vi) Permanent distortion of any planar surface of the diesel power package exceeding 0.04-inches/linear foot.

## 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.