Murphy 2 in. Pressure Swichgage 50 PSI with Knob Adjusting Face Contact - A20P-K-50


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0.45 LBS
Special Order Available:
Increments of 1

The Murphy Pressure Swichgage A20P-K-50 is a diaphragm-actuated, pressure-indicating gage with built-in electrical switches for tripping alarms and/or shutdown devices.  This rugged, built-to-last instrument is face sealed from the environment by the unique combination of a polycarbonate case and lens, a polished stainless steel bezel and O-ring seal. 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.

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. A20 Series applications include: engines/equipment in oil field, marine, irrigation, construction and trucking for lube oil pressure, water pump pressure, hydraulic pressure, air pressure, etc


  • 2 inch/51 mm dial
  • Sealed from the external environment 
  • Gage pointer makes with an adjustable contact to complete a pilot duty circuit
  • Compliance with EMC Council directive 89/336/EEC regarding electromagnetic compatibility except as noted


  • Murphy Part No.: A20P-K-50
  • Series: A20 Series
  • Base Model: A20P
  • Option: Knob Adjusting Face Contact
  • Range: 0-50 psi (0-345 kPa) [3.5 bar]
  • Dial: White on black, dual scale; U.S.A. standard scale is psi/kPa
  • Case: Polycarbonate/glass filled, corrosion-resistant; steel mounting clamp included
  • Bezel: Polished stainless steel, standard
  • Pointer: Tempered nickel silver; Red tip
  • Lens: Polycarbonate, high-impact
  • Temperature Range:
  • Ambient: -40° to 150°F (-40° to 66°C)
  • Process: -40° to 250°F (-40° to 121°C)
  • Process Connection: 1/8-27 NPTM brass
  • Sensing Element: Beryllium copper diaphragm
  • Gage Accuracy (% of Full Scale):
  • Lower 1/4: ±3%
  • Middle 1/2: ±2%
  • Upper 1/4: ±3%
  • Maximum Pressure: 100 psi (690 kPa)
  • Standard Setting: 10 psi (69 kPa) [0.8 bar]
  • Adjustable Limit Contact: SPST contact; pilot-duty only, 2A@30 VAC/DC; Closed when the low limit is met. Open when pointer is in normal operating range. Contacts are gold flashed silver.
  • Limit Contact Adjustment: by a 1/16 in. hex wrench through 100% of the scale.
  • Wiring: Number 4 screw terminals
  • Unit Weight: 8 oz. (0.23 kg)
  • Unit Dimensions: 3 x 3 x 3 in. (76 x 76 x 76 mm)

Product Condition: NEW

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