Murphy OPL Pressure Gauges


Quick Description

The Murphy OPL pressure gauges are combination pressure indicating gauges with adjustable low and high limit switches. Limit switches can be wired directly to electric pilot circuits to operate alarms, shutdown or the start/stop of engines and electric motors. Surface mount or panel mount enclosure is available for most versions. All versions feature a 4-1/2 in. (114 mm) dial for easy viewing. Adjustable limit switches are accessible from the front of the Swichgauge instrument. Limit contacts have self-cleaning motion to enhance electrical continuity.

Full Description
Product Variations
Part Number
Lead Time
0-300psi Switchgauge 4 1/2" (OPLFC)
- +
0-300psi Switchgauge (OPLC-DPCO)
- +
Total price: £0.00

Murphy OPL pressure gauges for engine protection in the event of out of tolerance pressure.

OPLC -DPCO (Picture Right)
The OPLC is a surface mount, indicating pressure gauge and switch. Adjustable high and low limit, ungrounded contacts are used to operate alarm, shutdown or start-stop circuits. Pointer closure against either of the adjustable contacts completes the pilot-duty circuit. An SPST toggle switch is provided to override the low limit contact for equipment startup. Suitable for engines or electric motors with appropriate Murphy magnetic switch or transformer relay assembly. Used in conjunction with AT03069 Throttle Controller

OPLFC (Picture Left)
The OPLFC is a panel mounting version of the OPLC. It has all of the features of the OPLC except the low limit contact lockout. The lockout must be done externally through the control circuit. The OPLFC is typically used in control panels for compressors, pumps, etc. This version can be environmentally sealed with either the ES or OS options. Contact lead termination is by pigtail wires.

Murphy OPL pressure gauges are part of the Murphy engine protection and monitoring range.

More information is available on the manufacturer website.


Case: Die cast aluminum; weatherproof.

Contact Ratings:
OPLC and OPLFC – 1 SPDT; Center off; 2A, 30 VDC / 1A, 125 VAC pilot duty
OPLBP – SPDT dry relay contacts; 10A, 125 VAC

Dial: 4-1/2 in. (114 mm) white on black, dual scaled psi /kPa

Gage Accuracy:  2-1-2 ±2% for the first and last quarters of the scale, the middle half is ±1%.

Geared Movement: 302 and 304 stainless steel.

Lens: Optically clear polycarbonate.

Pointer: High visibility with a pointer calibration hub.

Sensing Element: Select from bronze or 316 stainless steel bourdon tube.