Zone
The IEC scheme for how often a flammable atmosphere is present: Zone 0 (continuously or for long periods), Zone 1 (likely in normal operation) and Zone 2 (unlikely, and short-lived if it happens).
Piping inspection and supervision, explained from scratch
The IEC scheme for how often a flammable atmosphere is present: Zone 0 (continuously or for long periods), Zone 1 (likely in normal operation) and Zone 2 (unlikely, and short-lived if it happens).