Z Purge & Pressurization 1ZCF/BP/IS
|Purge Type||Z inert gas or air purge|
|Area:||Class I Div 2, Zone 2||Equipment Content:||Unclassified|
|Purging Action||Continous Flow||Same flow rate during and after purge|
|Enclosure Size||up to 17 cu ft||up to 0.39m3|
|Mounting Style||Back plate||Mounts externally on the enclosure wall. Minimal piping.|
|Alarm Output||Integral Switch – IS or NI||Volt free, Dry contact|
Install uncertified equipment in Class I Div 2 Gp A-D, Zone 2 IIC Ex (pz) hazardous areas.
A continuous flow of inert gas or compressed air purges hazardous gases from the enclosure, then,
Maintains a positive pressure to prevent hazardous gas creeping into the enclosure.
For enclosures with an internal source of flammable gas or vapour release, set the continuous air-flow rate to reduce the hazardous gas concentration below 25% of the Lower Flammable Limit (LFL), Lower Explosive Limit (LEL). Refer to IEC/EN 60079-2, or NPFA 496 before installing.
Z Purge units are manual units. The user sets the purge time by controlling the rate at which air flows into enclosure. Enclosure size based on 30 minute purge period and:
- 4 volume changes for ft3 – NFPA 496;
- 5 volume changes for m3 – IEC 60079-2.
Z Purge units are:
- Complete with:
- Control unit: controls air flow, monitors flow & pressure. Saves installation time & money, as mounts directly on enclosure with no costly interconnecting pipework;
- Spark arrestor: Fixed orifice measures flow through enclosure;
- Relief valve: Provides over-pressure protection. Fully compliant with latest standards as purge flow measured at relief value exhaust.
- Compact: Gain full use of enclosure’s internal space;
- Series Purging: Purge multiple enclosures with 1 unit. N.B application specific.
- Certified – IEC/EN 60079-2, NFPA 496:
Common Specifications of Z Purge units
- Control Unit: Inert gas or compressed air, clean, dry, free of flammable gases.
- Supply Pressure: 4 – 8 bar, 60 – 115 psi;
- Temperature Range: -20°C to 55°C, -4°F to 131°F;
- Supply Inlet: 1/4″ NPT(F). Connected with 1/2″ (12mm) O/D (min 3/8″, 10mm I/D pipe. 33ft, 10m Max Length.
- Relief Value: RLV 25 – Full 1″ bore
- Patented Magnetic Operation with integral spark arrestor;
- Opening Pressure: 1KPa, 10 mbar 4″ WC.
- Spark Arrestor Unit – SAU25: 8 orifice plates supplied for user selectable purge flow of:
- 0.4, 0.9, 1.4, 2.3, 3.2, 4.8, 6.4, 8.0 scfm;
- 10, 25, 40, 65, 90, 135, 180, 225 NI/min.
- Mounting: Back plate:
- Mounts either directly onto the outside or remote from the enclosure.
- Alarm Indicators:
- “Alarm”: Red indicates low pressure;
- “Pressurized” Green indicates pressure ok;
- Low pressure sensor alarm setting: 2.5 mbar, 1″ WC.
- Permissible Enclosure Leakage: 2 scfm, 60Nl/min
- Excellent corrosion resistance: 316L stainless steel, suitable for:
- Corrosive environments.
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