The gauge mechanism is enclosed in a steel case coated to resist corrosion. A polycarbonate, break-resistant lens and a polished, stainless steel bezel help protect this rugged, built-to-last instrument. 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 models 20P and 25P, 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 are grounded through the case and have self-cleaning motion to ensure electrical continuity.

The 20P-200 Pressure Swichgauge instrument has a 2 inch (51 mm) dial, and a pressure range of 0-200 psi. The gauge mechanism is enclosed in a steel case coated to resist corrosion, and utilizes a polycarbonate break-resistant lens and a polished stainless steel bezel to help protect this rugged instrument.

New MURPHY Swichgauge model 10-35-0949 fluid temperature gauge with high limit switch. Can be used with coolant, oil, diesel fuel or hydraulic fluid. 1/16" Hex wrench adjustment knob on front to adjust switch set point

The 20 Series (2 inch/51 mm dial) and the 25 Series (2-1/2 inch/64 mm dial) Swichgauge models are diaphragm-actuated, temperature-indicating gauges with built-in electrical switches for tripping alarms and/or shut-down devices.
Ranges are available from 32°-120°F (0°-45°C) through 300°-440°F (160°-220°C).
The gauge mechanism is enclosed in a steel case coated to resist corrosion. A polycarbonate, break- resistant lens and a polished, stainless steel bezel help protect this rugged, built-to-last instrument.

These vapor-actuated gauges feature a sealed capillary tube and a sensing bulb. When subjected to heat, the liquid in the sensing bulb changes to vapor creating pressure against the diaphragm mechanism. The diaphragm translates this vapor pressure into a mechanical gauge reading. For series 20T and 25T, the gauge pointer acts as a temperature indicator and as one switch pole which completes a circuit when it touches the adjustable limit contact. Contact(s) are grounded through the Swichgauge case. They have a self-cleaning motion to enhance electrical continuity.

Service Intended

The 20P Series (2 inch/51 mm dial) and the 25P Series (2-1/2 inch/64 mm dial) Swichgauge models are diaphragm-actuated, pressure-indicating gauges with built-in electrical switches. These switches are used for tripping alarms and/or shutdown devices.

Ranges are available from 0-15 psi (103 kPa) [1.0 bar] through 0-100 psi (690 kPa) [7.0 bar]. The gauge mechanism is enclosed in a steel case coated to resist corrosion. A polycarbonate, break-resistant lens and a polished, stainless steel bezel help protect this rugged, built-to-last instrument. 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 models 20P and 25P, 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 are grounded through the case and have self-cleaning motion to ensure electrical continuity. Model 20PE has internal snap-acting SPDT switches. gauge-only models, without the switches (Murphygauge®) are also available.

Service Intended

The 25DP and A25DP Series (2-1/2 inch/64 mm dial) Swichgauge 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 25DP series mechanism is enclosed in a steel case coated to resist corrosion. The A25DP series has a polycarbonate case sealed from the environment. Both feature a polycarbonate, break-resistant lens to help protect the 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.

Service Intended

The 25DP and A25DP Series (2-1/2 inch/64 mm dial) Swichgauge 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 25DP series mechanism is enclosed in a steel case coated to resist corrosion. The A25DP series has a polycarbonate case sealed from the environment. Both feature a polycarbonate, break-resistant lens to help protect the 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.

Service Intended

The 45APE Series gauge instrument is a mechanical gauge for pressure indication. It includes two adjustable SPDT switches. These snap-acting switches can be used for start and stop, to trip alarms and to shut down equipment. Ranges are available from 30 psi (207 kPa) [2.06 bar] thru 5,000 psi (34.48 MPa) [344.73 bar].

The 45APE Series utilizes a bourdon tube sensing unit with a stainless steel dual-sector geared movement. Each of the sectors drives separate pointers when pressure is applied to the bourdon tube. The indicating pointer (visible pointer) shows actual pressure reading, including below and beyond the low and high trip points. The low and high trip points are adjustable independently on the gauge front lens. The switch operator pointer (behind the dial) is calibrated to follow the indicating pointer. The low and high trip point indicators arrest the switch operator pointer. As pressure decreases or increases through the principal of lost motion, the respective snapswitch is tripped.

The 45APE Series models are widely used in applications requiring pressure indication and Form C low and high pressure switches.

• Combination Indicating gauge with Independent Low and High Snap-Acting Switches
• Field-Adjustable and Highly Visible Low and High Pressure Trip Point Indicators
• Dual-Sector Geared Movement Allows for Full-Scale Indication and Set Point Control
• Panel and Surface Mount Versions Available
• Latching Control Relay Versions Available

Service Intended

The OPL-series pressure gauge instruments 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 gauge. Limit contacts have self-cleaning motion to enhance electrical continuity.

• Combination Indicating gauge and Critical Pressure Limit Switches
• High and Low Pressure Limit Contacts Are Visible and Adjustable
• Panel and Surface Mount Versions
• Indicating-only gauge Available
• Latching Control Relay Versions Available

Service Intended

The OPL-series pressure gauge instruments 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 gauge. Limit contacts have self-cleaning motion to enhance electrical continuity.

• Combination Indicating gauge and Critical Pressure Limit Switches
• High and Low Pressure Limit Contacts Are Visible and Adjustable
• Panel and Surface Mount Versions
• Indicating-only gauge Available
• Latching Control Relay Versions Available

Service Intended

The 20 Series (2 inch/51 mm dial) and the 25 Series (2-1/2 inch/64 mm dial) Swichgauge models are diaphragm-actuated, temperature-indicating gauges with built-in electrical switches for tripping alarms and/or shut-down devices. Ranges are available from 32°-120°F (0°-45°C) through 300°-440°F (160°-220°C). The gauge mechanism is enclosed in a steel case coated to resist corrosion. A polycarbonate, break- resistant lens and a polished, stainless steel bezel help protect this rugged, built-to-last instrument. These vapor-actuated gauges feature a sealed capillary tube and a sensing bulb. When subjected to heat, the liquid in the sensing bulb changes to vapor creating pressure against the diaphragm mechanism. The diaphragm translates this vapor pressure into a mechanical gauge reading. For series 20T and 25T, the gauge pointer acts as a temperature indicator and as one switch pole which completes a circuit when it touches the adjustable limit contact. Contact(s) are grounded through the Swichgauge case. They have a self-cleaning motion to enhance electrical continuity. These instruments are used on equipment in oil field and monitoring engine coolant, crankcase oil and transmission oil.

• Combination Indicating gauge and Limit Switch
• Critical/High Temperature Limit Switch Is Visible and Adjustable (Most Models)
• Switch Can Activate Alarms and/or Shut Down Equipment
• Contact Grounds Through Case

Service Intended

The SDB Series are direct-mounting temperature devices. They provide an accurate direct-reading gauge with an adjustable limit switch to activate alarms and/or shutdown. A knob on front of the instrument allows you to adjust the limit switch trip point. Pointer movement is actuated by a bi-metallic sensing element. Models SDB500, SDB501 and SDB500EX have a temperature range of 100° to 500°F (40° to 260°C). SDB500EX enclosure is explosion-proof and CSA listed for Class I, Group C and D hazardous locations. The SDB1000 has a temperature range of 200° to 1000°F (100° to 500°C). The most common use of the SDB Series is to monitor gas compressor temperatures. Engine exhaust temperature can also be monitored to indicate overloading or lean fuel mixtures, or use the SDB to help coordinate loads on twin-engine installations

• Easy to read dial
• Bi-metallic sensor
• Two ranges:
  - 100 to 500°F (40 to 260°C)
  - 200 to 1000°F (100 to 500°C)
• Dials scaled in degrees fahrenheit celsius
• CSA listed explosion-proof model available

Service Intended

The 4-1/2” (114 mm) size dial gauge is a mechanical gauge for temperature indication. It is a combination indicating gauge and critical temperature limit switches. High and low temperature limit contacts are visible.

It includes adjustable, electrical contacts that can be used for start and stop, to trip alarms and to shut down equipment.

Panel and wall-mount versions are available as well as latching control relay versions.

Ranges are available from 15° to 250° F (9° to 121° C) through 260° to 450° F (127° to 232° C).

Typical applications include:

Gas compressors
Heaters and coolers
Water pump temperature
Engine coolant temperature
Process temperature
Basic Models

• Combination indicating gauge and critical temperature limit switches
• High and low temperature limit contacts are visible and adjustable
• Panel and wall mount versions
• Latching control relay versions available