Instonnic

✅ Nitrogen Purging in Control Panel – Technical Specification 1. Purpose

To displace ambient air (which may contain moisture, oxygen, or flammable gases) from the control panel or enclosure by injecting dry nitrogen gas. This prevents:

• Condensation and corrosion

• Arc flashes

• Contamination

• Explosive atmospheres (in hazardous zones)

🛠️ Technical Specification 1. Purging Medium

• Gas Used: Dry Nitrogen (N₂)

• Purity: ≥99.99% (typically industrial or UHP grade)

• Dew Point: ≤ -40°C (to ensure moisture removal)

2. Pressure & Flow Requirements

• Inlet Pressure: 2 to 10 bar (regulated)

• Flow Rate:

  • Initial Purge: 5 to 20 L/min (depending on panel volume)

  • Continuous Flow: 0.2 to 1 L/min (trickle purge for pressurization or humidity control)

3. Enclosure/Panel Compatibility

• Volume: Typically applicable to enclosures from 5 to 500 liters

• Material: Compatible with stainless steel, mild steel, or aluminum enclosures

• Sealing: Enclosure should be well-sealed with minimal leak rate (ideally <0.1 bar/h)

4. Inlet Fittings and Components

• Inlet Port: 1/8” or 1/4” NPT/BSP (Female)

• Tubing Material: Nylon or stainless steel tubing (6 mm, 8 mm OD)

• Shutoff Valve: Manual or solenoid type

• Flow Restrictor or Needle Valve: To control trickle flow

• Check Valve: To prevent backflow of ambient air

5. Pressure & Flow Control Devices

• Regulator:

  • Range: 0–10 bar output

  • Type: Single-stage or dual-stage (for cylinder-fed systems)

• Flow Meter / Rotameter:

  • Range: 0–25 L/min

  • Scale: Calibrated for nitrogen

  • Type: Inline or panel-mount

• Pressure Gauge:

  • Range: 0–10 bar

  • Accuracy: ±1.6% FS

  • Dial: 50–63 mm (optional digital type)

6. Purge/Pressurization Cycle Control (Optional Automation)

• Purge Timer Relay: For setting initial purge duration (e.g., 5–15 minutes)

• Enclosure Pressure Switch: Monitors internal pressure (for automatic shutoff)

• Humidity Sensor (optional): Shuts off nitrogen when RH < 20% inside panel

7. Exhaust/Vent Port

• Exhaust Port: 1/8" or 1/4" NPT (with orifice to control purge rate)

• Exhaust Location: Must be at the opposite side from inlet (top or side of panel)

• Check Valve or Flame Arrestor: Optional for hazardous area applications

8. Mounting

• Internal or external panel-mounted regulator and flow components

• Skid or wall-mounted purge systems (for multi-panel setup)

9. Electrical (if applicable)

• Solenoid Valve Supply: 24V DC or 230V AC

• Control Panel Interface: Dry contacts for pressure or humidity alarms

• Purge System Enclosure: IP65 or higher (if outdoor/external)

10. Safety & Standards Compliance

• Applicable Standards:

  • IEC 60079-2 (for pressurized enclosures in hazardous zones)

  • NFPA 496 (Purge and Pressurization standard)