Expo-Telektron Safety Systems MiniPurge Z & Y Purge Manual ...

Expo-Telektron MiniPurge Z purge Handbook ML 307 Issue A
6.6.6 Adjustments and settings
The user adjustable settings are as follows:
For continuous flow (CF) systems only – purge flow rate orifice size selection
Leakage Compensation valve / Continuous Flow valve
6.6.7 Purge time
If no specific purge test has been performed on the pressurized enclosure, the volume of the
pressurized enclosure must be determined by the manufacturer or user of the pressurized
C:\Main System Files\Marketing\Memo\ML307 ISSUE A.doc
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enclosure, and the necessary purging time calculated based on the purge flow rate specified by
the “standard" or "code” being used. It is the user's responsibility to verify or enter this data on
the pressurized enclosure (label supplied) and/or Mini-Z-Purge and Mini-Y-Purge system
nameplate. Ask Expo-Telektron if in doubt.
For North America, NFPA 496 standard permits 4 complete volume changes for enclosures
except when the pressurized enclosure is an electric motor then 10 internal free volume
changes are required.
If the pressurized enclosure external dimensions indicate a total volume of 8 cubic foot, the
following is based on using a 1*LC/ at a purge flow rate of 8 scfm
8 cubic foot enclosure volume x 4 volume changes = 4 minutes purge time
8 cubic foot/minute purge flow rate
If the same pressurized enclosure is a motor, then,
8 cubic foot enclosure volume x 10 volume changes = 10 minutes purge time
Note:
8 cubic foot/minute purge flow rate
1*LC = 8scfm purge flow rate
2*LC = 16scfm purge flow rate
3*LC = 32scfm purge flow rate
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