New old protection concepts for non electrical Ex besides Ex h

Protection concepts of types of protection “d”, “p” and “t” acceptable for non-electrical equipment.
The protection concepts for the types of protection “d”, “p” and “t” are based respectively on the types of protection available for electrical equipment:
• “d” defined in IEC 60079-1,
• “p” defined in IEC 60079-2 and,
• “t” defined in IEC 60079-31.
All technical requirements apply.
The nature and ignition sources of non-electrical equipment shall be considered when applying types of protection “d”, “p”, or “t” to Ex non-electrical equipment.
Keep up good work!