30 CFR § 77.304 - Explosion release vents.

---
identifier: "/us/cfr/t30/s77.304"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "30 CFR § 77.304 - Explosion release vents."
title_number: 30
title_name: "Mineral Resources"
section_number: "77.304"
section_name: "Explosion release vents."
chapter_name: "MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR"
subchapter_number: "O"
subchapter_name: "COAL MINE SAFETY AND HEALTH"
part_number: "77"
part_name: "MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES"
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. 811."
regulatory_source: "36 FR 9364, May 22, 1971, unless otherwise noted."
cfr_part: "77"
---


# 77.304 Explosion release vents.

Drying chambers, dry-dust collectors, ductwork connecting dryers to dust collectors, and ductwork between dust collectors and discharge stacks shall be protected with explosion release vents which open directly to the outside atmosphere, and all such vents shall be:

(a) Hinged to prevent dislodgment;

(b) Designed and constructed to permit checking and testing by manual operation; and

(c) Equal in size to the cross-sectional area of the collector vortex finder when used to vent dry dust collectors.