What is the specified width of a flame path for a plane flange joint to be permissible?

The specified width of a flame path for a plane flange joint being permissible is one inch. This width is critical in ensuring safety in mining operations, particularly in environments where flammable gases or dust may be present. A flame path acts as a barrier to prevent the passage of flame from one area to another, and maintaining a width of one inch helps to minimize the risk of a flame traveling beyond the containment area.

In practical terms, this means that any joints or connections that do not meet this minimum width may not adequately prevent the transmission of flames, thereby increasing the potential for explosive accidents or fire incidents in a mine. Therefore, adhering to this standard is vital for the safety of all personnel and the protection of equipment in mining operations.