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

Motor Pre-Start Ventilation Systems (3PV, 5PV, 7PV)

IECEx & ATEX certified pre-start ventilation systems for large Ex e & Ex n electrical machines


  • Certification to +60°C
  • Pre-start ventilation flow capacity up to 14,000 Nl/min
  • Remote start options
  • Stainless steel enclosure construction

Configure your product

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


Got a question?

For more information contact your local partner to speak to one of our purge and pressurization experts or contact us.

  • Description
  • Specifications
  • Downloads
  • Certificates
  • Manuals
  • 3D Models


Expo’s PV range of pre-start ventilation systems provide essential protection to large non-sparking electric motors. The PV range can deliver pre-start ventilation flow rates of up to 14,000 Nl/min and is ideal for very large sized Ex e and Ex n electrical machines.

The system comprises the Control Unit (CU) and the Relief Valve (RLV). The Control Unit contains the pneumatic logic to monitor and control air flow, pressure and pre-start ventilation timing, and provides the system outputs. The RLV measures air flow at the outlet and provides over-pressure protection for the machine.



Air Inlet
Instrument quality air, 4-10 barg
Pre-start ventilation flow rate
User selectable:
3PV: 500, 1,000, 1,500 Nl/min
5PV: 2, 3, 4, 5, 6,000 NI/min.
7PV: 7, 8, 10, 12, 14,000 Nl/min
Temperature range
-20°C to +60°C
Pre-start ventilation timer
1-99 minutes
Timer power source
IS (Intrinsically Safe) Battery or Electro-Pneumatic Power Supply (EPPS)
Signal Inputs/Outputs
Inputs: Remote start (if option selected) Outputs: Ventilation in progress; Ventilation complete. Connection: Ex e junction box Optional Ex i, Ex d junction boxes.

* Not all certifications may apply to all system variants. Check the specific Operating & Maintenance Manual for details.