Type RPE is used for reheating gas supplying pressure reducing regulator pilots. Type RPE avoids the inconveniences caused by freezing which occur during large pressure drops. There are two versions of the Type RPE:

Electrical Pilot Heater
Type RPE (with a heating element) is installed with the thermometer in the vertical position and is affixed to the actuator bolts of the regulator. A thermostat and power relay must be installed in a non-explosive risk zone.

Regulator Bottom Electrical Heater
The version is normally used for relief lines. Type RPE is assembled with four screws to the bottom of the regulator. Type RPE can be installed in a hazardous atmosphere.  Type RPE must be installed between the pilot filter and the pre-expansion relay.

Type RPE is in conformity with the Directive for Equipment or Protective System intended for use in potentially explosive atmospheres 94/9/CE.
It is classified under group II, Category 2.