PURGE SYSTEM SELECTION WIZARD
QUOTE WITH MODEL #
PURGE DILUTION
TIME CALCULATOR



Hazardous Area Classification

Nonhazardous and / or Unclassified: An area, location, or atmosphere, which is known to not contain any concentrations of ignitable or flammable vapor, gas, liquid, and / or dust.

Division 2 and / or Zone 2: An area, location, or atmosphere, which is known not to contain any concentrations of ignitable or flammable vapor, gas, liquid, and / or dust during normal operation and if it should occur will exist only during short periods, such as equipment failure, breakdown, or service and maintenance. 
Division 1 and / or Zone 1: An area, location, or atmosphere, which is known to contain concentrations of ignitable or flammable vapor, gas, liquid, and / or dust during normal operation and will exist frequently because of equipment failure, breakdown, or service and maintenance.

Division 1 and / or Zone 0: An area, location, or atmosphere, which is known to contain concentrations of ignitable or flammable vapor, gas, liquid, and / or dust, which is present continuously or for long periods of time.


Types of Purging Definitions

Type Z - Purge: Type Z purging reduces the classification within a protected enclosure from Division 2 and / or Zone 2 to nonhazardous. Failure to maintain pressure within the protected enclosure shall be detected by an alarm or indicator. The dilution purge time can be a manual operation and once the enclosure has been purged of ignitable or flammable concentrations, only positive pressure is required to be maintained within the enclosure and it is not necessary to remove power from the protected equipment upon the loss of purge pressure. 

Type Y - Purge: Type Y purging reduces the classification within the protected enclosure from Division 1 and / or Zone 1 to Division 2 and / or Zone 2. All equipment in the protected enclosure shall be approved for Division 2 and / or Zone 2 locations. Failure to maintain pressure within the protected enclosure shall be detected by an alarm or indicator. The dilution purge time can be a manual operation and once the enclosure has been purged of ignitable or flammable concentrations, only positive pressure is required to be maintained within the enclosure and it is not necessary to remove power from the protected equipment upon the loss of purge pressure.

Purge Gas Inlet Definitions
Continuous Dilution Purge Gas Inlet: Continuous dilution is a method of maintaining pressure in an electronics enclosure in which after the electronics enclosure has been diluted below the required lower explosive limit (LEL) the protective gas is passed continuously through the electronics enclosure at a pressure above that of the required 0.20 inches H2O (0.50 mbar) and discharged to the outside atmosphere through an exhaust vent. The same volume of purge gas is maintained during and after the dilution time cycle. Continuous dilution is normally used for maintaining and controlling heat buildup from the electronics within the pressurized enclosure by continuously exchanging purge gas through the electronics enclosure to atmosphere. Leakage Compensation Purge Gas Inlet: Leakage compensation allows a higher volume of protective gas supply to be manually or automatically selected to speed up dilution time of potentially flammable materials to an acceptable level, permitting a more-rapid application of initial power, or restoration of power to protected electrical equipment, after service. When the dilution cycle has elapsed, the large volume of purge gas can be manually or automatically turned off, which allows a volume of purge gas larger than the leak rate of the electronics enclosure to be introduced into the now protected electronics enclosure to maintain at least 0.20 inches H2O (0.50 mbar). Leakage compensation is normally used to conserve purge gas when utilities are at a premium.


Nonhazardous and / or Unclassified: An area, location, or atmosphere, which is known to not contain any concentrations of ignitable or flammable vapor, gas, liquid, and or dust.
Division 2 and / or Zone 2: An area, location, or atmosphere, which is known not to contain any concentrations of ignitable or flammable vapor, gas, liquid, and / or dust during normal operation and if it should occur will exist only during short periods, such as equipment failure, breakdown, or service and maintenance.
Division 1 and / or Zone 1: An area, location, or atmosphere, which is known to contain concentrations of ignitable or flammable vapor, gas, liquid, and / or dust during normal operation and will exist frequently because of equipment failure, breakdown, or service and maintenance.
Division 1 and / or Zone 0: An area, location, or atmosphere, which is known to contain concentrations of ignitable or flammable vapor, gas, liquid, and / or dust, which is present continuously or for long periods of time.
Type Z-Purge: Type Z purging reduces the classification within a protected enclosure from Division 2 and / or Zone 2 to nonhazardous. Failure to maintain pressure within the protected enclosure shall be detected by an alarm or indicator. The dilution purge time can be a manual operation and once the enclosure has been purged of ignitable or flammable concentrations, only positive pressure is required to be maintained within the enclosure and it is not necessary to remove power from the protected equipment upon the loss of purge pressure.
Type Y-Purge: Type Y purging reduces the classification within the protected enclosure from Division 1 and / or Zone 1 to Division 2 and / or Zone 2. All equipment in the protected enclosure shall be approved for Division 2 and / or Zone 2 locations. Failure to maintain pressure within the protected enclosure shall be detected by an alarm or indicator. The dilution purge time can be a manual operation and once the enclosure has been purged of ignitable or flammable concentrations, only positive pressure is required to be maintained within the enclosure and it is not necessary to remove power from the protected equipment upon the loss of purge pressure.

Type X-Purge: Type X purging reduces the classification within the protected enclosure from Division 1 and / or Zone 1 to nonhazardous. Failure to maintain pressure within the protected enclosure and / or adequate exhaust flow from enclosure vent shall be detected by an alarm or indicator. The dilution purge time shall be an automatically controlled operation and once the enclosure has been purged of ignitable or flammable concentrations, only positive pressure and adequate exhaust flow from enclosure vent are required to be maintained within the protected enclosure. However, it is necessary to remove power from the protected equipment upon the loss of purge pressure and / or inadequate exhaust flow from enclosure vent.
Continuous Dilution Purge Gas Inlet: Continuous dilution is a method of maintaining pressure in an electronics enclosure in which after the electronics enclosure has been diluted below the required lower explosive limit (LEL) the protective gas is passed continuously through the electronics enclosure at a pressure above that of the required 0.20 inches H2O (0.50 mbar) and discharged to the outside atmosphere through an exhaust vent. The same volume of purge gas is maintained during and after the dilution time cycle. Continuous dilution is normally used for maintaining and controlling heat buildup from the electronics within the pressurized enclosure by continuously exchanging purge gas through the electronics enclosure to atmosphere.

Leakage Compensation Purge Gas Inlet: Leakage compensation allows a higher volume of protective gas supply to be manually or automatically selected to speed up dilution time of potentially flammable materials to an acceptable level, permitting a more-rapid application of initial power, or restoration of power to protected electrical equipment, after service. When the dilution cycle has elapsed, the large volume of purge gas can be manually or automatically turned off, which allows a volume of purge gas larger than the leak rate of the electronics enclosure to be introduced into the now protected electronics enclosure to maintain at least 0.20 inches H2O (0.50 mbar). Leakage compensation is normally used to conserve purge gas when utilities are at a premium.