Brand: Murphy

Murphy B-Series Murphygage Pressure, Vacuum and Temperature Gauge

Name: Murphy B-Series Murphygage Engine Gauge – Datasheet & Quote
Brand: Murphy
SKU: B-Series Murphygage

Description

Compact gauge-only instrument for engine pressure, vacuum and temperature

The Murphy B-Series Murphygage is a diaphragm-actuated indicating gauge from Enovation Controls. It uses the heavy-duty design of the 20 and 25 Series Swichgage but is more compact and has no switch, so the bulletin calls it the optimum instrument for gauge-only applications. It has a high-impact polycarbonate lens, a sturdy steel case and a polished, low-profile stainless steel bezel.

The same family covers three measurements. The pressure version shows pressure changes at the diaphragm on an analog dial and has a removable pulsation dampener in the port to limit pointer flutter. The vacuum version is available in 0 to 20 or 0 to 30 in. Hg (0 to -68 or 0 to -102 kPa). The temperature version uses a sensing bulb whose fluid vaporizes and presses on the diaphragm, with a copper capillary in PVC armor as standard and galvanized steel or 316 stainless steel armor as options.

Technical specifications

Values are from Enovation Controls bulletin 96012.

Parameter	Specification
Measurements	Pressure, vacuum and temperature versions
Dial	White on black; USA standard is dual scale; others available
Pressure and vacuum accuracy, up to 300 psi (24 bar)	+/-3% of full scale in the lower quarter, +/-2% in the middle half, +/-3% in the upper quarter
Pressure accuracy, 400 psi (28 bar)	+/-3% lower quarter, +/-3% middle half, +/-5% upper quarter
Vacuum ranges	0-20 in. Hg or 0-30 in. Hg (0 to -68 or 0 to -102 kPa)
Temperature ranges	32-120, 32-160, 130-220, 130-250, 140-300, 160-320, 180-350 and 300-440 F (Celsius equivalents on the dial)
Ambient temperature, pressure/vacuum	-40 to 150 F (-40 to 66 C)
Process temperature, pressure/vacuum	-40 to 250 F (-40 to 121 C)
Sensing element	Beryllium copper diaphragm
Port	Brass
Case and bezel	Plated steel with mounting clamp (except direct mount models); polished stainless steel bezel, other bezels optional
Pointer and lens	White pointer on black dial, black on white dial; high-impact polycarbonate lens
Maximum panel thickness	1/4 in (6 mm)

How the Murphygage diaphragm is held

The bulletin explains the difference from many other gauges. In the Murphygage the diaphragm is held firmly between a back plate and the mounting plate, so the gauge case does not form part of the sensing chamber. In many other designs the diaphragm and an expansion retarding plate are soldered into the case port, and damage to the case in that area can affect diaphragm operation.

On the pressure instruments the dampener can be removed for periodic cleaning when the gauge is used with liquids that might clog it, which helps keep response and accuracy.

Choosing between B-Series, 20 Series and 25 Series

Choose the B-Series when you only need to read pressure, vacuum or temperature and do not need an alarm or shutdown contact. If the application needs a contact, the 20P / 25P and 20T / 25T Swichgage models are the switch-equipped relatives. The bulletin recommends using it on industrial engines and equipment in oil field, marine, irrigation, construction and trucking service, including engine coolant, crankcase oil and transmission oil.

For temperature versions, optional capillary lengths, engine adaptors, sensing bulbs and range combinations are covered in Murphy bulletin T-8428B, which is not part of this file. Confirm measurement type, range, scale, port thread, capillary length and bezel before ordering. Enovation Controls lists this product family on its Legacy Products page, which describes those items as less popular or outdated but still available for purchase. Confirm current availability and any replacement part before ordering.

Where the B-Series Murphygage is used

Engine oil pressure monitoring
Vacuum monitoring on engine intakes and filters
Engine coolant temperature
Gauge-only panel positions
Compact instrument panels

Selection checklist for the B-Series Murphygage

Pressure, vacuum or temperature version
Pressure range
Vacuum range
Temperature range
Dial scale
Capillary length and armor
Panel or direct mount
Bezel type

Installation, commissioning and maintenance notes for the B-Series Murphygage

Cut the panel hole and fit the gauge with its mounting clamp. Keep the panel thickness within 6 mm. Connect the port to the pressure or vacuum source. Route the temperature capillary away from sharp edges. Check the reading against a known reference at the first start.

Requesting a quotation for the Murphy B-Series Murphygage

Please send the measurement type, the range and the mounting style. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

B-Series Murphygage manufacturer

It is made by Enovation Controls.

B-Series Murphygage gauge type

It is a diaphragm-actuated indicating gauge.

B-Series Murphygage switch

It has no switch and is used for gauge-only needs.

B-Series Murphygage lens

The lens is high-impact polycarbonate.

B-Series Murphygage case

The case is sturdy steel.

B-Series Murphygage bezel

The standard bezel is polished stainless steel with a low profile.

B-Series Murphygage dial

The dial is white on black, with a dual scale as the USA standard.

B-Series Murphygage pulsation dampener

A removable dampener in the port limits pointer flutter.

B-Series Murphygage vacuum ranges

Vacuum ranges are 0 to 20 and 0 to 30 in. Hg.

B-Series Murphygage temperature sensing

A bulb with vaporizing fluid presses on the diaphragm.

B-Series Murphygage capillary armor

The capillary is copper in PVC armor, with steel options.

B-Series Murphygage ambient temperature

The ambient range is minus 40 to 150 degrees F.

B-Series Murphygage process temperature

The process range is minus 40 to 250 degrees F.

B-Series Murphygage sensing element

The sensing element is a beryllium copper diaphragm.

B-Series Murphygage port

The port is brass.

B-Series Murphygage panel thickness

The maximum panel thickness is 1/4 in or 6 mm.

B-Series Murphygage bulletin

The data comes from Enovation Controls bulletin 96012.

Gauge records for the B-Series Murphygage

Record the range, the dial scale and the mounting position.

Choosing the right B-Series Murphygage range

Choose the range so normal readings sit in the middle of the dial.

Documents and quotation

The attached bulletin 96012 (revision 2014/10/10) is the source for the values above. Seven Star LLC supplies Murphy products as an independent supplier in Muscat. Send the exact model code, range and options with your enquiry. See other pressure instrumentation for related items.

Datasheets & Documents

Datasheet Murphy B-Series Murphygage instrument bulletin 96012 (rev. 2014/10/10) Download

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About brand

Murphy is an American brand of engine and equipment protection controls that began in 1939 in Tulsa, Oklahoma. Founder Frank W. (Pat) Murphy combined an indicating gauge with a switch that stops an engine on low oil pressure or high coolant temperature, first installed on unattended oilfield engines. That SWICHGAGE remains the brand's best-known product.

Seven Star LLC is an independent supplier in Muscat. We list selected Murphy gauges, switches and controllers for engines, generator sets, pumps and compressors in Oman and the GCC.

Murphy company profile

Founded	1939, Tulsa, Oklahoma, USA, by Frank W. (Pat) Murphy
First product	The SWICHGAGE, a gauge with a built-in shutdown switch
Original market	Unattended engines in oilfields
Product families	SWICHGAGE gauges and switches, TATTLETALE annunciators, PowerView displays, engine and compressor control panels, liquid level switches and vibration switches

Milestones

1939: Pat Murphy develops the Murphy safety switch and starts FW Murphy in Tulsa.
Today: SWICHGAGE gauges are still among Murphy's best-selling products.

Murphy product series

The classic range includes the 20P and 25P pressure Swichgage and the 20T and 25T temperature Swichgage, gauges with built-in switch contacts for alarm and shutdown, B-Series Murphygage gauges, the L150 and EL150K1 level Swichgage, ESPS-100 and ESTS senders and switches, Tattletale annunciators and magnetic switches, the VS2 shock and vibration switch, the MP3298 magnetic pickup and exhaust pyrometers for diesel engines.

Newer products include the PowerCore MPC-20 configurable engine controller and the PowerView 780B 7-inch display with CAN J1939 communication, and the Sentinel 300P battery charger keeps starting batteries charged.

Where Murphy products are used

Gas compressor packages, engine-driven pumps and fire pumps, generator sets, irrigation and dewatering pumps and mobile equipment, where the instruments protect the engine against low oil pressure, high temperature, overspeed and vibration.

Murphy products we list

Family	Examples
Pressure Instrumentation	20P / 25P Series Pressure Swichgage Gaug…, B-Series Murphygage Pressure, ESPS-100 / ESTS Engine Pressure and Temp…
Temperature Instrumentation	10705147 Single-Port and 10705146 Dual-P…, 20T / 25T Series Temperature Swichgage G…
Vibration Monitoring	MP3298 Magnetic Pickup for Engine Speed…, VS2 Series Shock and Vibration Switch
Level Instrumentation	L150 / EL150K1 Level Swichgage for Engin…
UPS and Batteries	Sentinel 300P Series Programmable Switch…
Controllers & Data Acquisition	Tattletale Annunciators and Magnetic Swi…

Ordering Murphy parts: what we need

Send the full model code, range or scale, thread, voltage and any options. Because many Murphy parts are legacy designs, we check configuration and current availability against Enovation Controls documents before quoting.

Facts checked against the Murphy history published by Enovation Controls, October 2026.

Browse Murphy products by category: Pressure Instrumentation, Vibration Monitoring, Controllers & Data Acquisition, Level Instrumentation, Temperature Instrumentation.