The ePurge X is a next-generation purge controller with fully automated purge and pressurization functions. Bearing a slim and compact profile, this unit mounts directly onto an electronics enclosure and protrudes less than inch from the surface. High-visibility LED status indicators are used to fully convey the enclosure status at a glance.

In order to prevent fire or explosion, instrument enclosures are often "purged" of flammable gas. Before cycling power to the instrument, compressed air is used to displace any compounds that might ignite. A positive pressure is then maintained inside the enclosure to keep any flammable elements from leaking in.


Using a digital mass flow sensor, the ePurge X actively measures the purge gas flow rate to determine how long the enclosure must be purged before receiving power. The unit only confirms the purge once an amount of purge gas equivalent to five times the enclosure volume has been cycled through. By contrast, conventional purge controllers use pneumatic timing, whereby purge duration is fixed based on manual user calculation. This method can err on the long side (prolonging downtime) or, in case of inconsistent utility air, confirm an unsafe and incomplete purge.


While a threshold pressure differential must be maintained between the enclosure's interior and its surroundings, any pressurization exceeding that level is simply wasting utilities. A differential pressure sensor is used to monitor this parameter. Additionally, using the flow rate measured at the digital mass flow sensor, the ePurge X can output a real-time value for instrument air usage. The differential pressure and the instrument air flow are used to produce a control signal; this signal communicates exactly how much instrument air flow is needed to maintain the threshold pressurization.

This intelligent optimization feature will dramatically reduce the waste of expensive utilities. Countless factors can cause differential pressure to fluctuate: enclosure leakage, ambient weather, etc. This variability means that the potential savings from optimization are significant. Assuming an average usage excess of 3 SCFM of compressed air (typical for a large enclosure) and the fully loaded cost of compressed air ($0.0004/ft3), the ePurge X can pay for itself within five years by utility savings alone.

General Performance

Purge Verification

Digital mass flow sensor verifying purge gas cycle (equaling 5x enclosure volume)


Factory calibrated; re-calibration requires simply inputting new target enclsoure dimensions

Purge Gas

Instrument compressed air
Operating Conditions

Purge Pressure

Minimum: 4 bar (60 psi)
Maximum: 8 bar (115 psi

Operating Temperature

-20 °C to 55 °C


6.5" L x 3.75" W x 3.06" D
Surface Protrusion: 0.74"

Wetted Materials

Stainless steel 316L & anodized aluminum

Hazardous Area Classification

NEC: Class 1, Division 1, Groups C, D
IEC: Zone 1, Group IIB

Power Consumption

7 watts (maximum)

Alarm Output

Dry-contact relay signal & LED indicator
For your convenience, we offer two types of quotations. Based on the current completeness of your project information, please select from the RFQ options below:
  • Provides budgetary quote only (non-binding)
  • Requires only basic contact information and a measurement description