info at expoworldwide dot com

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
Z purge. Back Plate Mounting. Continuous flow inert gas or compressed air purge unit for Class I Div 2  Gp A-D,  Zone 2 IIC Ex (pz) hazardous areas.1ZCF/BP/IS


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:
    • ATEX,
    • cFMus,
    • cULus,
    • IECEx,
    • INMETRO.

Common Specifications of Z Purge units

Typical specifications:

  • 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:
    • Offshore;
    • Corrosive environments.

Data Sheet