FW Murphy Temperature Gages

Murphy's heavy-duty mechanical Swichgage® and Murphygage® temperature instruments feature rugged industrial-rated diaphragm movement, a tough PVC-armored capillary, plated steel case, polycarbonate lens and a stainless steel bezel. The gages are available in 2, 2.5 and 4.5 inches (51, 64, and 114 mm). The 4.5-inch version features a bourdon tube sensing element, plus adjustable high and low limit contacts or snap-acting switches. Murphy's “A-series” products include environmental sealing to keep out damaging condensation.

 

20T and 25T Series Temperature Swichgage®

murphy.20TThe 20 Series (2 inch/51 mm dial) and the 25 Series (2-1/2 inch/64 mm dial) Swichgage models are diaphragm-actuated, temperature-indicating gages, with built-in electrical switches for tripping alarms and/or shutdown devices.

Ranges are available from 32-120°F (0-45°C) thru 300-440°F (160-220°C).

The gage 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 gages 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 gage reading.

For series 20T and 25T, the gage 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 Swichgage case. They have self-cleaning motion to enhance electrical continuity.

Models 20TE and 25TE have internal snap-acting SPDT switches.

Gage-only models, without contacts (Murphygage® instruments) are also available.

Applications

Industrial engines and equipment in Oil Field, Marine, Irrigation, Construction and Trucking industries. Monitoring Engine Coolant, Crankcase Oil, Transmission Oil.

Literature

• Sales Bulletin (pdf)
• Installation Instructions (pdf)
• Sensing Bulb, Scale, Capillary Length Combinations (pdf)
• Capillary, Bulb, Adapter, Thermowell Specifications (pdf)

A20T and A25T Series Temperature Swichgage®

murphy.A20TThe A20 Series (2 inch/51 mm dial) and the A25 Series (2-1/2 inch/64 mm dial) Swichgage® models are diaphragm-actuated, temperature-indicating gages, with built-in electrical switches for tripping alarms and/or shutdown devices.

Ranges are available from 32-120°F (0-45°C) thru 300-440°F (160-220°C).

All models of these rugged, built-to-last instruments are fully sealed from the environment by the unique combination of a polycarbonate case and lens, a polished stainless steel bezel, and O-ring seals.

These vapor/pressure actuated gages 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 a diaphragm mechanism. The diaphragm translates this vapor pressure into a mechanical gage reading.

For series A20T and A25T, the gage 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 isolated from ground. They have self-cleaning motion to enhance electrical continuity.

Models A20TE and A25TE have internal snap-acting SPDT switches.

Gage-only models, without contacts (Murphygage® instruments) are also available.

Applications

Applications for A20 and A25 Series temperature Swichgage instruments include: engines and equipment in Oil Field, Marine, Irrigation, Construction and Trucking industries. Monitoring Engine Coolant temperature, Crankcase Oil, Transmission Oil.

Literature

• Sales Bulletin (pdf)
• Installation Instructions (pdf)
• Sensing Bulb, Scale, Capillary Length Combinations (pdf)
• Capillary, Bulb, Adapter, Thermowell Specifications (pdf)

Direct Mount Temperature Switch: TSB Series

murphy.TSBThe TSB switch is a direct mount switch for temperature sensing. It has one limit contact that can be used to activate an alarm, actuate indicator lights or shut down equipment.

The construction of this instrument is the same as our time-proven Swichgage® . A precision machined brass mounting plate and port captures a high quality stamped beryllium copper diaphragm. The single-pole, double-throw (SPDT) snap switch is operated directly from the diaphragm, for quick acting and positive switching. Trip point may be factory preset according to your specifications.

Housing is weather sealed to prevent entry of moisture, dust, etc. A glass-filled nylon terminal block with quick-screw terminal connections gives the TSB switch a real advantage in industrial engine applications. The TSB is ideal when reading is not desired, but temperature is critical to operational efficiency.

Intended for use in general purpose non-classified areas.

Applications

• Engine Coolant
• Irrigation Systems
• Compressors
• Oil Field Systems
• Engine Lubrication
• Construction equipment
• Mobile Equipment
• Marine Engines
• Generators
• Electric Motors

Features

• Fits most engine applications
• SPDT snap-switch
• Activates indicator lights, alarms or shut down equipment
• Time-proven Swichgage construction
• Easy wiring terminal block
• Steel housing specially coated to resist corrosion
• Trip point is factory preset to your specifications (minimum quantities apply)

Literature

• Sales Bulletin (pdf)

Direct Mount Temperature Switchgage®: SDB Series

murphy.SDBThe SDB Series are direct-mounting temperature Swichgage 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 Swichgage 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°F to 500°F (40°C 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°F to 1000°F (100°C to 500°C).



Basic Operation

SDB500, SDB501 and SDB1000: When the indicating pointer on the SDB touches the adjustable contact, a one-wire-to-ground circuit is completed to shut down the equipment and/or actuate audible or visual alarms. Proper relays or Tattletale ® annunciators (magnetic switches) must be incorporated into the system.

SDB500EX: When the temperature rises to the preset trip point, the pointer engages an internal SPDT snap-switch to close/open circuits.

Applications

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.

Literature

• Sales Bulletin/Installation Instructions (pdf)

 

Exhaust Pyrometers

murphy.pyrometerThe Single Port and Dual Port Pyrometers monitor exhaust temperatures in all types of engines. The Dual Port Pyrometer can monitor each bank of a V-type engine, allowing you to compare readings at all times.

Both pyrometers feature an easy-to-read illuminated dial with scales in both Fahrenheit and Celsius. They require no outside power (except for dial lighting). Spring loaded jewels and alloy pivots increase durability. Murphy offers pyrometer accessories such as thermocouples and wire lead assembly.


Applications

Excessive exhaust temperature is a major damaging factor to all engines. The best way to monitor this temperature is with the use of a pyrometer. Excessive exhaust temperature is caused by an upset fuel/air ratio or more fuel in the engine than there is air to support it. This condition can occur as a result of over throttling, a dirty air cleaner, different fuels, a malfunctioning fuel system, change of altitude, an out of tune engine and many other causes. But whatever the cause, a pyrometer indicates this condition before serious damage occurs. Suitable for stationary or mobile engines, power units, agricultural and construction equipment, as well as marine and trucking.

Features

• Large sweep scales for maximum legibility
• Internal illumination for night use
• Accuracy: 2% full scale
• Sealed housing
• Ambient temperature compensation
• Calibrated permanently at 2/3 scale
• Flush type mounting on any plane

Benefits of Using a Pyrometer

• Longer engine life
• Better fuel economy
• Less lubrication oil dilution
• Lubrication oil stays clean much longer
• Exhaust emissions drop to a minimum
• Malfunctions indicated before excessive damage occurs

Literature

• Sales Bulletin (pdf)
• Installation Instructions (pdf)

SPL and 45TE Series Dial Temperature Swichgage®

murphy.SPLFCThe 4-1/2 in. (114 mm) dial size Swichgage® is a mechanical gage for temperature indication. It includes adjustable, electrical contacts that can be used for start and stop, to trip alarms and to shut down equipment.

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

Basic Operation

This vapor actuated gage features a sealed capillary tube and sensing bulb. When subjected to heat, the liquid in the sensing bulb expands to vapor creating pressure against a bourdon tube mechanism. The bourdon tube translates this vapor pressure into a mechanical gage reading. For models SPLC and SPLFC, the gage pointer acts as a pressure indicator and as one switch pole which completes a circuit when it touches the adjustable limit contacts. Contacts have self-cleaning motion to ensure electrical continuity. A toggle switch is provided on SPLC models to override the low contact for equipment start-up.

Models 45TE and 45TEF have internal snap-acting SPDT switches.

Applications

• Gas Compressors
• Engine Coolant Temperature
• Process Temperature
• Heaters and Coolers
• Water Pump Temperature

Literature

• Sales Bulletin (pdf)
• Installation Instructions (pdf)

TC, RTD, and RTDT Series Thermocouple Assemblies

Murphy offers a variety of highly reliable thermocouple and RTD (Resistance Temperature Detector) assemblies and 4-20 mA DC output RTD transmitters.

Their innovative features include a 304 stainless steel thermowell that provides protection to the spring-loaded element.

The cast aluminum connecting head meets NEMA 4 requirements and includes an RTD transmitter or a thermocouple/RTD terminal block mounted on ceramic Steatite and rated NEC Class 2.

The complete assemblies are offered in 2-1/2, 4-1/2, or 7-1/2 in. (63, 114, or 191 mm) thermowell insertion lengths.

Thermocouple Assemblies with Thermowell
Available in types J or K, the thermocouple assemblies have ungrounded elements in a 304 stainless steel spring loaded sheath. Replacement parts and thermocouple extension wire are available.

RTD Assemblies with Thermowell
Resistance temperature detector (RTD) assemblies are available with a 100 ohm platinum element, 3-wire leads, and spring loaded 316L stainless steel element sheath.

RTD Transmitter Assemblies with Thermowell
RTDT assemblies transmit process variable temperatures. Available as part of the temperature sensor assemblies or as a separate units, the RTDT’s accept 2 or 3 wire, 100 ohm RTD’s. The RTD transmitters are loop powered, they feature linearized 4-20 mA DC outputs and have reversed polarity protection.

Applications

Murphy’s temperature sensing assemblies fit in a variety of industrial processes and applications. Their ruggedness and characteristics make these assemblies a popular and price-competitive choice.

Literature

• Sales Bulletin (pdf)
• Installation Instructions (pdf)

Thermocouple, 1/4" Diameter Stainless Steel Tube Type

murphy.thermocoupleDue to the increase in controller and telemetry applications, this thermocouple product line has been added to the line up of Murphy temperature monitoring end devices. They are designed to fit as many applications as possible with the fewest possible parts and the fewest possible installation caused faults.

Most of the thermocouple failures occur in how the thermocouples extension wire is installed and connected. This new line incorporates Type K, 20 AWG stranded extension wire encased in a rugged cable to meet demanding environments. The extension wire lengths are available in 5’, 15', 30’, 50’, and 100’ lengths. This will enable a run from the point of measurement to the nearest conduit entry or to be installed in a cable tray. The industry standard yellow Teflon allows easy identification of K type thermocouple wires so they can be separated from high voltage wires following good installation practices. 

Thermowells are available in 2”, 4-1/2”, or 7-1/2” lengths for insertion depth and have a 1/2” NPT process connection. They are supplied with a standard stainless steel compression fitting for securing the thermocouple in the thermowell at the appropriate depth. In low pressure applications the thermocouple can be inserted directly into the process through a standard 1/4” stainless steel tubing compression fitting.

The thermocouples are encased in a 1/4” diameter 316 stainless steel tubing sheath with stainless steel Bell Spring for strain relief. The initial offerings are K type thermocouples with 6” and 10” long 1/4” diameter probes. The thermocouples are shipped straight, but can be bent with standard tubing benders anywhere along its length to a 90° angle to minimize clearance required and help prevent damage due to personnel working on the unit. The thermocouple is tip sensitive to minimize ambient temperature influence and should be inserted between 25% and 75% of the piping inside diameter or enough to minimize any skin temperature affect on the tip of the probe when installed in vessels.

Additional Features

• Stainless steel transition sealing gland with a stainless steel Bell Spring for strain relief.

• Standard bore through stainless steel compression fitting for securing the thermocouple in the thermowell at the appropriate depth.

• Can be inserted directly into a low-pressure application process through a standard 1/4” stainless steel bore through tubing compression fitting.

• Enables a run from the point of measurement to the nearest conduit entry, junction box, or all the way to the panel housing the readout and monitoring instrument. Can also be installed in a cable tray.

• The thermowelll assembly comes with a stainless steel bore through compression fitting and ferrel saving installation time and money.

Literature

• Sales Bulletin (pdf)



 
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