Z Purge & Pressurization 1ZLC/BP/IS
|Purge Type||Z inert gas or air purge|
|Area:||Class I Div 2, Zone 2||Equipment Content:||Unclassified|
|Purging Action||Leakage Compensation||High flow rate during purge.
Then compensation for leakage
|Enclosure Size||up to 60 cu ft||up to 1.35m3|
|Mounting Style||Back plate||Mounts externally on the enclosure wall. Minimal piping.|
|Alarm Output||Integral Switch – IS or NI||Volt free, Dry contact|
Install any equipment in a Class I Div 2 Gp A-D, Zone 2 IIC Ex [pz] and Zone 22 Ex [pD] hazardous area.
Leakage compensation operates by:
- Initially providing high air or inert gas volumes to rapidly purge hazardous gas from the enclosure;
- Then providing low air or inert gas volumes, sufficient to maintain a higher pressure inside the enclosure than the surrounding hazardous area, and to compensate for leaks from the enclosure.
Leakage compensation improve equipment uptime, and reduces running costs. It:
- Improves equipment uptime, by reducing downtime caused by purging;
- Reduces costs, by minizing compressed air or inert gas consumption during operation.
Note: The enclosure size assumes a 30 minute purge period and:
- 4 volume changes for ft3 i.e. required by NFPA 496;
- 5 volume changes for m3 i.e. required by IEC 60079-2.
The standards do not specify a minimum or maximum purge time. Select an appropriate Purge Flow sensor for your enclosure size, and desired purge time.
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;
- Relief valve: Open during purging, and measures the gas or air flow through the enclosure. Closes after purging, when in leakage compensation mode.
- Compact: Gain full use of enclosure’s internal space;
- Series Purging: Purge multiple enclosures with 1 unit. N.B application specific.
- Certified: Fully compliant as direct purge flow measurement at Relief Valve exhaust, required by IEC/EN 60079-2, NFPA 496:
Common Specifications of Z Purge units
- Purge Sensor: Select size:
- Size 1: 8 scfm, 225 Nl/min for enclosures 60 cu ft, 1.35m3;
- Size 2: 16 scfm, 450 Nl/min for enclosures 120 cu ft, 2.7m3;
- Size 3: 32 scfm, 900 Nl/min for enclosures 240 cu ft, 5.4m3;
- 1/4″, 6mm pipe required between Control Unit and Relief Valve, installed inside the purged enclosure.
- Supply Pipe: Provide:
- Size 1 & 2: 1/2″, 15mm O/D;
- Size 3: 3/4″, 20mm;
- Max length: 20ft, 6 m.
- 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;
- Relief Value: RLV 25 – Full 1″ bore
- Patented Magnetic Operation with integral spark arrestor;
- Opening Pressure: 1KPa, 10 mbar 4″ WC.
- Manual Purge Flow: ON/OFF lever.
- Mounting: Back plate:
- Mounts either directly onto the outside or remote from the enclosure.
- Alarm Indicators:
- Red: “Alarm”indicates low pressure;
- Green: “Pressurized” indicates pressure ok;
- Yellow: “Purge Flow” purging the enclosure;
- 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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