§ 23.6. General requirements for approval.
37 words·~1 min read·
/us/cfr/t30/s§ 23.6·A research copy — for the controlling text, always check the official state or federal source. Not legal advice.
Telephones and signaling devices shall be durable in construction, practical in operation, and suitable for conditions of underground service. They shall offer no probable explosion hazard under normal operation if use in gassy or dusty mine atmospheres.