Skip to main content
Simplifying Complexity. Delivering Safety.
Simplifying Complexity.
Delivering Safety.

Purge & Pressurization Systems for Electrical Enclosures

Expo is a world leader in the design and manufacture of purge & pressurization systems for electrical enclosures, analysers and other equipment.

All electrical equipment used in hazardous areas is required to be certified using a recognised protection method. While users may have a choice of methods for protection, purge and pressurization (Ex p) is the simplest and most flexible solution. Download our Purge Systems brochure here.

Read more here in our whitepaper: "Purge and Pressurisation - Advantages, Methods and Guidelines."

Use the table below to choose a system suitable for your application

Flammable Gas / Vapour
Ignitable Dust
Hazardous area classification
Zone 1
Class I Div 1
Zone 2
Class I Div 2
Zone 21
Class II Div 1
Zone 22
Class II Div 2
Standard Industrial Environment
MiniPurge system (Pneumatic control)
Pressurisation only MiniEPS
SmartPurge (Electronic control)

Custom Purge Systems

Our Mini-Purge and SmartPurge platforms are very flexible, and can work across a very wide range of application areas. However, if your application needs something different, then Expo can develop a custom solution. 

Please call +44 (0) 20 8398 8011 to speak to one of our purge and pressurization experts or contact us.

Range Overview

Expo’s purge and pressurization systems will allow your electrical equipment to be used in most hazardous areas with virtually no limitations on the type of equipment that can be protected.

Our systems are approved for use in gas and dust environments under ATEX, IECEx, NEC and most other certification schemes for Zone 1&2, 21 & 22; Class I Div 1&2, Class II Div 1&2; Class I Zone 1&2, Class II Zone 21 and 22.

Flammable gas or vapour hazards – our purge and pressurization systems can operate in two modes:  

Leakage Compensation (LC) – the most commonly used, this method purges the enclosure with a high flow for a preset time, then reduces the flow to a level sufficient to maintain overpressure, compensating for any enclosure leakage.

Continuous Flow (CF) – Once purge is completed, the high purge flow rate is maintained into the enclosure. This is typically used when the enclosure contains a source of flammable gas, such as a gas analyser, and dilution is required as part of compliance with the certification standard.

Dust hazards -  dust purges are required to operate as pressurization systems only.

Environmental Pressurization Systems - Some non-hazardous environments can still be harmful to electrical equipment if dirt, dust or corrosive gases build up inside the enclosure. Pressurization systems are used to prevent ingress into the enclosure.

Download our Purge Systems brochure here.


  • Proven solutions for electrical enclosure protection and OEM products
  • Large, global installed base
  • Can purge very large enclosures, or multiple enclosures in series

Configure your product

Use our product configurator tool to build a system to your exact specification.