30 CFR § 7.307 - Static pressure test.

---
identifier: "/us/cfr/t30/s7.307"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "30 CFR § 7.307 - Static pressure test."
title_number: 30
title_name: "Mineral Resources"
section_number: "7.307"
section_name: "Static pressure test."
chapter_name: "MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR"
subchapter_number: "B"
subchapter_name: "TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS"
part_number: "7"
part_name: "TESTING BY APPLICANT OR THIRD PARTY"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "30 U.S.C. 957."
regulatory_source: "53 FR 23500, June 22, 1988, unless otherwise noted."
cfr_part: "7"
---


# 7.307 Static pressure test.

(a) *Test procedure.* (1) The enclosure shall be internally pressurized to a minimum of 150 psig and the pressure maintained for a minimum of 10 seconds.

(2) Following the pressure hold, the pressure shall be removed and the pressurizing agent removed from the enclosure.

(b) *Acceptable performance.* (1) The enclosure during pressurization shall not exhibit—

(i) Leakage through welds or casting; or

(ii) Rupture of any part that affects the explosion-proof integrity of the enclosure.

(2) The enclosure following removal of the pressurizing agent shall not exhibit—

(i) Visible cracks in welds;

(ii) Permanent deformation exceeding 0.040 inches per linear foot; or

(iii) Clearances, in excess of those specified in this subpart, along accessible flame-arresting paths, following any necessary retightening of fastenings.