info at expoworldwide dot com

Purge & Pressurization for Motors

Purge & Pressurization for Motors

Expo Ex p Purge and Pressurization systems enables safe installation of all electric motors in Class 1 Div 1 to Class 2 Div 2, Zone 1 or Zone 2 hazardous areaMotor Purge System

Expo’s motor purge and pressurization control units enable you to install electric motors in gas and dust hazardous areas.

Your motors will meet ATEX or IECEx requirements for Zone 1 / Zone 2 and Zone 21 / Zone 22.  In the US, NFPA70 (The National Electrical Code NEC) describes:

  • Purging: Supply an enclosure with a protective gas at sufficient flow and positive pressure so as to reduce the concentration of flammable gas or vapor to an acceptable level;
  • Pressurization: Supply an enclosure with a protective gas, with or without continuous flow, at sufficient pressure to prevent the entrance of  flammable gas, vapor, combustible dust, or ignitable fiber.

Usually, the “Authority Having Jurisdiction” assesses and approves the motor. To ease this process,  Expo motor purge systems include:

  • Documentation to simplify local assessment of motors.
  • Electrical interfaces with UL listing or CSA approval to your specification.

Expo Motor Purge & Pressurization System’s Benefits

Cost effective: Purge & Pressurization is the easiest,  lowest-cost protection for large electric motors in hazardous areas

Eliminate spurious motor trips due to low internal air pressure,  with Expo's Closed Loop Automatic Pressurization System. 316SST enclosure and Ex e junction box

Eliminate spurious motor trips and associated restart delays. Expo developed CLAPS – Closed Loop Automatic Pressurization System. It:

  • Prevents internal air-pressure drops due to sudden load or operating temperature changes. Without CLAPS, the motor trips due to low internal air-pressure;
  • Maintains enclosure’s air pressure because it is a fast, high-gain, high-capacity regulator;
  • Injects high air volumes, restoring the enclosure’s air pressure.

Remove Explosionproof housings: design construction and certification of such housing is expensive, time-consuming and difficult.  For purge and pressurization, the motor housing should be sufficiently:

  • Robust to support slight over pressure ~50 mbar/1.5″ WG;
  • Tight to minimise leakage during normal running.
IEC 60079-2 (2007) fully compliant purge and pressurized motor housing. Note that 3 pipes not 2 pipes connect to the relief valvePurged Motor Under Test

Flexible systems design:

  • Flow rates for all motor sizes: 500 Nl/min to 14000 Nl/min;
  • Electronic timer: accurate and repeatable purge times;
  • Ex e junction box & terminals. Options: Ex i, Ex d.

Local Indicators: for Alarm, Pressurized Purging. Options include:

  • Intermediate – LOLO;
  • Secondary (junction box) Alarms.

Robust 316L stainless-steel housings:

  • secure, corrosion-resistant, all-welded construction.

Guaranteed Performance and Site Acceptance:

  • 60 years experience:  designed hundreds of systems;
  • Strategic partner:  to  all  major OEM’s and skid-builders.

Options for Expo Motor Purge & Pressurization Systems

Customers often request these configuration options:

Pre-Start Ventilation for “Special Measures”:  Often, safe-starting high-voltage Ex e and Ex n motors requires “special measures”. Such “special measures arise from 60079-7 and 60079-15 risk assessments.

The UK Health & Safety Executive  states that “special measures”, i.e.  Pre-Start Purging or Ventilation,  would have prevented the accidental ignitions described in this Offshore Information Sheet No. 3/2010

Expo’s Pre-Start Ventilation features:

Pre Start Ventilation 3PV where IEC Ex 60079-7 and 60079-15 require special mesures.Pre-Start Ventilation
  • Zone 1 ATEX/IECEx approved: replaces Expo’s  Zone 2 PP system under our Manufacturers Declaration;
  • Local Indicators & Controls: e.g. dedicated local start push-button;
  • Airflow for all motor sizes:  200 Nl/min to 14,000 Nl/min.

Customers’ often request:

  • Remote Start interfaces: from Motor Control Center or Distributed Control system;
  • Powered Outlet Valve: For where  air-pressure alone won’t always open the outlet;
  • Extended running: Prevents delays where process conditions cause motor trips after start-up. When the Pre-Start Ventilation cycle completes, a permissive contact closes. However, purge air flows until manual reset.

Timers: either Electronic or Pneumatic:

  • Electronic: Intrinsic Safety (I.S.). Highly accurate and repeatable. Ensure the motor is available when the plant becomes available.
  • Pneumatic: Robust, requires no electric power.

Electrical Interfaces: we match your onsite wiring preferences, e.g.:

  • Increased safety junction box with terminals for all signals;
  • Intrinsically safe terminals for alarm signals;
  • Explosionproof or flameproof junction box with terminals.

Pressure Alarms & Interfaces:

  • Motor interlock (permissive contacts)
  • Alarm / pressurized contact
  • Purge complete / purge in progress / intermediate pressure / secondary pressure contacts

Expo Motor Purge Customers

We are proud that our customers include:

Motor Purge and Pressurization Ex p IEC 60079-2 (2007) & NFPA496 protects hazardous areas Class 1 Div 1 to Class 2 Div 2,  Zone 1, Zone 2, Zone 21, Zone 22 for ABB's customers
Motor Purge and Pressurization Ex p IEC 60079-2 (2007) & NFPA496 protects hazardous areas Class 1 Div 1 to Class 2 Div 2, Zone 1, Zone 2, Zone 21, Zone 22 for Siemens' customers
Motor Purge and Pressurization Ex p IEC 60079-2 (2007) & NFPA496 protects hazardous areas Class 1 Div 1 to Class 2 Div 2, Zone 1, Zone 2, Zone 21, Zone 22for Toshiba-Mitsubishi's customers
Motor Purge and Pressurization  Ex p IEC 60079-2 (2007) & NFPA496 protects hazardous areas Class 1 Div 1 to Class 2 Div 2, Zone 1, Zone 2, Zone 21, Zone 22 for Scorch's customers
Expo  Motor Purge and Pressurization systems, Ex p IEC 60079-2 (2007)  protect GE's customers
Expo  Motor Purge and Pressurization systems, Ex p IEC 60079-2 (2007)  protects Brush's customers
Expo  Motor Purge and Pressurization systems, Ex p IEC 60079-2 (2007) & NFPA496 protects hazardous areas Class 1 Div 1 to Class 2 Div 2, Zone 1, Zone 2, Zone 21, Zone 22 for Lawrence Scott's customers
Expo  Motor Purge and Pressurization systems, Ex p IEC 60079-2 (2007) & NFPA496 protects  hazardous areas Class 1 Div 1 to Class 2 Div 2, Zone 1, Zone 2, Zone 21, Zone 22 for Ansaldo's customers
Expo  Motor Purge and Pressurization systems, Ex p IEC 60079-2 (2007) & NFPA496 protects  hazardous areas Class 1 Div 1 to Class 2 Div 2, Zone 1, Zone 2, Zone 21, Zone 22 for  protect Hyundai's customers

Datasheets

Motor Purge Datasheets:

Certificates

USA and Candada Certificates

IECEx Certificates

ATEX Certificates

INMETRO Certificates

We’d like to earn your business

We’d be delighted to discuss your requirements. For

  • North America contact Matthew Dudones;
  • Rest of World contact Mike O’Neill.

Your Name (required)

Your Email (required)

Organisation

Subject

Your Message