UL 60079-2-2017 pdf free download

UL 60079-2-2017 pdf free download.Explosive Atmospheres – Part 2 : Equipment Protection by Pressurized Enclosure”P”.
The manufacturer should carefully consider damage to a potentially fragile containment system by adverse operating conditions. The Instructions should provide suitable guidance to reduce the risk of damage for those conditions agreed between manufacturer and user such as vibration, thermal shock and maintenance operations when doors or access covers of the pressurized enclosure are open.
12.3 Containment system with a limited release
The design of a containment system with limited release shall be such that the rate of release of the flammable substance is predictable in all conditions of containment system failure. The quantity of flammable substance released into the pressurized enclosure includes the quantity of flammable substance in the containment system and the flow of the flammable substance entering the containment system from the process. The flow shall be limited to a predictable rate by appropriate flow limiting devices, fitted outside the pressurized enclosure.
However, if that part of the containment system from the entry point into the pressurized enclosure up to and including the inlet to the flow limiting device conforms to 12.2, the flow limiting device may be installed inside the pressurized enclosure, in which case the flow limiting device shall be permanently secured and shall have no movable parts.
The process flow into the containment system need not be limited if the maximum release rate from the containment system into the pressurized enclosure can be predicted. This condition can be met when:
a) the containment system comprises connected parts which individually meet the requirements of 12.2 and the joints between the parts are so constructed that the maximum release rate can be predicted and the joints are permanently secured; or
b) the containment system includes orifices, or nozzles, for the purpose of release in normal operation (for example, flames) but otherwise meets the requirements of 12.2.
12.3DV.1 DE Modification of Clause 12.3, fourth paragraph to replace with the following:
12.3DV.1.1 lithe flow limiting device is not included as part of the equipment. the eertfieate number- shell include the-”X” auffixE In—accordance with-the mefklng -requirements of lEG 60079-0-end the Specific Conditions of Use listed-on-Ihe-certifleete in accordance with UL 60079-0 shall detail the necessary Information required by the user to ensure conformity with the requirements of this standard Including the maximum pressure and flow of the flammable substance Into the containment system.
Pressurized enclosures containing a flame shall be assessed as though the flame had been extinguished. The maximum quantity of the fuel/air mixture which supplies the flame shall be added to the quantity of release from the containment system.UL 60079-2-2017 pdf free download.