Velcon Differential Pressure Module (DPM™) Now Available!

Joint Inspection Group (JIG) Bulletin No. 58, January 2013 requires…

 “All existing hydrant servicers with filter monitor vessels shall have a dP switching device (or PLC system) installed by December 31st, 2013.”

The Class 1 Zone 2 DPM constantly monitors the differential pressure of a filter/monitor vessel. The DPM is fully compliant with JIG Bulletin No. 58 and works with a variety of pressure inputs include differential pressure gauges, pressure transducers and momentary switches.

Operating the DPM

The DPM is typically installed on a mobile aviation refueling vehicle and is electronically integrated into the mandatory “deadman” system of these vehicles. In the event that the differential pressure rises above 22 psi (1.5 bar), an industrial strength relay built into the DPM is triggered. This action breaks the refueling vehicle’s “deadman” circuit, causing an immediate shutdown of the refueling operation.  Resetting of the DPM can only be done via a latching key switch.

Future Proof!

The DPM is also future proof as it is can be easily upgraded to the full featured Flow Differential Pressure Module (FDPM®) MKII in less than 30 minutes.  Simply exchange the front cover with an interactive touch screen and add flow input.  The touch screen display adds features such as displaying of real-time flow rates and calculated corrected differential pressure.  For the ultimate in flow corrected differential pressure monitoring, consider Velcon’s FDPM.

For additional details on the DPM, please visit  Details on Velcon’s FDPM can also be found by visiting