A20P / A25P Series


The A20 Series (2 inch/51 mm dial) and the A25 Series (2-1/2 inch/64 mm dial) Swichgage instruments are diaphragm-actuated, pressure-indicating gages with built-in electrical switches for tripping alarms and/or shutdown devices.

FW Murphy Production Controls offers support for all our products. If you are unable to find the product that you need, please call us at 918-957-1000.

Stage V: 
Product Overview: 

Ranges are available from 0-30 psi (207 kPa) [2.0 bar] through 0-300 psi (2.1 MPa) [20 bar].

These rugged, instruments are face sealed from the environment by the unique combination of a polycarbonate case and lens, a polished stainless steel bezel and O-ring seals. Tese gages are sealed from the external environment.  Accuracy and protection from moderate overpressure is assured by a unique, unitized diaphragm chamber. A built-in pulsation dampener helps eliminate pointer flutter and is removable for cleaning.

For series A25P, the gage 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.

Model A20PE has internal snap-acting SPDT switches for three wire control and can be wired to make or to break a circuit.

Gage-only models, without switches (Murphygage instrument) are also available.

A20/A25 Series applications include: engines/equipment in oil field for lube oil pressure, water pump pressure, hydraulic pressure, air pressure, etc.

Base Models

A25P Series Swichgage
The gage pointer makes with an adjustable contact to complete a pilot duty circuit.

A20PE Swichgage
A20PE (was A20EO). Features internal snap-acting SPDT switches, instead of the single pole/pointer contacts. When the switch closes on falling pressure, it becomes set, as pressure rises the switch resets (refer to wiring diagram).

A20PG Murphygage instrument
Gage without contact(s)