This part of IEC 60079 contains the specific requirements for the construction and testing of electrical pressurized equipment, of Type of Protection “p”, intended for use in explosive gas atmospheres or explosive dust atmospheres. It also includes the requirements for pressurized equipment containing a limited release of a flammable substance within the pressurized equipment.
This part of IEC 60079 supplements and modifies the general requirements of IEC 60079-0, except as indicated in Table 1. Where a requirement of this part of IEC 60079 conflicts with a requirement of IEC 60079-0, the requirements of this standard take precedence.
This standard does not include the requirements for:
• pressurized equipment where the containment system within the pressurized equipment can release
a) air with an oxygen content greater than normal (typically 21% v/v), or
b) oxygen in combination with inert gas where the oxygen is in a proportion greater than 21 % v/v.
c) other oxidizers present in the flammable substance.
• pressurized rooms or analyzer houses/rooms; see IEC 60079-13;
• pressurized equipment used where “explosives” or pyrotechnics are present;
• pressurized equipment used where hybrid mixtures of gas/vapour and combustible dust are present;
• pressurized equipment used where pyrophoric substances such as explosives or propellants containing their own oxidizers are present • pressurized equipment with an internal source of release of combustible dust.
• pressurized equipment which uses gas detectors to modify or eliminate purging criteria.