30 CFR Part 57Public Domain

§ 57.22215 — Separation of intake and return air (I-A, II-A, III, and V-A mines)

Subpart T — Safety Standards for Methane in Metal and Nonmetal Mines

Main intake and return air currents shall be coursed through separate mine openings and shall be separated throughout the mine, except—

(a)Where multiple shafts are used for ventilation and a single shaft contains a curtain wall or partition for separation of air currents. Such wall or partition shall be constructed of reinforced concrete or other noncombustible equivalent, and provided with pressure-relief devices.

(b)During development of openings to the surface—

(1)Ventilation tubing approved by MSHA in accordance with 30 CFR part 7 or previously issued a BC or VT acceptance number by the MSHA Approval and Certification Center may be used for separation of main air currents in the same opening. Flexible ventilation tubing shall not exceed 250 feet in length.

(2)Only development related to making a primary ventilation connection may be performed beyond 250 feet of the shaft.

← Previous§ 57.22214 Next →§ 57.22216

Public Domain: 30 CFR Part 57 (MSHA Safety and Health Standards — Underground Metal and Nonmetal Mines) is a U.S. government publication and is not subject to copyright. Text extracted from the official source ↗. Figures are served from the eCFR; if one does not load, use the link in its place.