The 20DP and A20DP Series (2 inch/51 mm dial) and the 25DP and A25DP Series (2-1/2 inch/64 mm dial) Swichgage instruments are diaphragm-actuated, differential pressure-indicating gauges with a built-in electrical switch. This switch is used for tripping alarms and/or shutting down equipment. These gauges are intended to monitor and indicate oil, fuel or water filter restriction and can reduce the risk of dangerously high pressure which may rupture the filter, resulting in contaminants entering the system.

The 20DP and 25DP series mechanism is enclosed in a steel case coated to resist corrosion. The A20DP and A25DP series have a polycarbonate case and are sealed from the environment. All feature a polycarbonate, break-resistant lens and a polished, stainless steel bezel to help protect these rugged, built-to-last instruments.

The gauge pointer acts as a pressure indicator and as one switch pole which completes a circuit when it touches the adjustable limit contact. Contacts have self-cleaning motion to ensure electrical continuity.

Additional Features:

  • Constant visual indication of the condition of your filter is shown on the dial.
  • Two instruments in one with an accurate indicating gauge and adjustable p.s.i.d. limit switch reduces inventory and installation time.
  • Adjustable contact lets you set the monitoring range of the gauge. The contact is tamper proof and can be set only with a 1/16 Allen-head wrench.
  • All gauges are made of durable materials allowing them to withstand rugged applications.
  • Early filter changes cost you money and increase the risk of contaminants entering the system. A Murphy filter restriction Swichgage instrument will let you know when to change the filter and maintain peak efficiency.