End Devices
The 20 Series (2 inch/51 mm dial) and the 25 Series (2-1/2 inch/64 mm dial) Swichgage models are diaphragm-actuated, pressure indicating gages with built-in electrical switches. These switches exceed SAE standards and are used for tripping alarms and/or shut-down devices.
Ranges are available from 0-15 psi (103 kPa) [1.0 bar] through 0-400 psi (2.8 MPa) [28 bar]. 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. 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 gage 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.
Sales Bulletin: 20P/25P Series
94116 rev. 2014/10/04
The A20 Series (2 inch/51 mm dial) and the A25 Series (2-1/2 inch/64 mm dial) Swichgage instruments are diaphragm-actuated, pressure-indicating gages with built-in electrical switches for tripping alarms and/or shutdown devices. Ranges are available from 0-15 psi (103 kPa) [1.0 bar] through 0-400 psi (2.8 MPa) [28 bar].
These rugged, built-to-last instruments are face sealed from the environment by the unique combination of a polycarbonate case and lens, a polished stainless steel bezel and O-ring seals. Ranges above 30 psi (207 kPa) [2 bar] are sealed from the external environment (except PE Series). Ranges of 30 psi and lower have a small weep hole in the bottom of the case. 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 series A20P and A25P, 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.
Sales Bulletin: A20P/A25P Series
94030 rev. 2014/10/10
The 20DP and A20DP Series (2 inch/51 mm dial) Swichgage instruments are diaphragm-actuated, differential pressure-indicating gages with a built-in electrical switch. This switch is used for tripping alarms and/or shutting down equipment. These gages 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 20DP series mechanism is enclosed in a steel case coated to resist corrosion. The A20DP series has a polycarbonate case and are sealed from the environment. All feature a polycarbonate, break-resistant lens and a polished, stainless steel bezel to help protect these rugged, built-to-last instruments.
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.
Sales Bulletin: 20DP/25DP/A20DP/A25DP Series
96014 rev. 2014/10/04
The B-Series Murphygage instrument is a high-quality, diaphragm-actuated indicating gage. Built by Enovation Controls with the same heavy-duty design as the standard 20 series and 25 series Swichgage instrument, the B-gage is more compact and is the optimum instrument for gage-only applications. It has a high impact polycarbonate lens, sturdy steel case and a polished, low-profile stainless steel bezel.
Accuracy and protection from moderate over-pressure/over-temperature are assured by a unique, unitized diaphragm chamber, superior quality materials and the design of the gage movement.
Pressure Murphygage Instrument
Pressure changes at the diaphragm convert to accurate mechanical movements that are indicated on an easy-to-read analog dial. A pulsation dampener in the pressure port helps eliminate pointer flutter. It can be removed for cleaning to maintain the gage’s response and accuracy.
Vacuum Murphygage Instrument
Available in 0 to 20 or 0 to 30 in. Hg. (0 to -68 or 0 to -102 kPa) vacuum.
Temperature Murphygage Instrument
As temperature rises, the fluid in the sensing bulb vaporizes to apply pressure on the diaphragm. The movement translates this vapor pressure to a calibrated reading of temperature on the dial. The standard capillary is copper with a PVC armor. Optional armor covering is galvanized steel or 316 stainless steel (specify). Optional bulb types, adaptor nuts and thermowells are available.
The B-Series can be utilized in industrial engines and equipment in the oil field, marine, irrigation, construction and trucking industries as well as monitoring engine coolant, crankcase oil and transmission oil.
Sales Bulletin: B Series Murphygage Instrument
96012 rev. 2014/10/10
The OPL Series pressure gauge instruments are combination pressure-indicating gauges with adjustable low and high limit switches.
The OPL Series 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 enclosures are available for most versions. All versions feature a 4-1/2 in. (114 mm) dial for easy viewing.
Features include:
· Combination indicating gauge and critical pressure limit switches
· Adjustable high and low pressure limit contacts are accessible from the front of the gauge
· Limit contacts have self-cleaning motion to enhance electrical continuity
· Both panel-mount and surface-mount versions
· Available indicating-only gauge, without contacts
· Available built-in latching relay version for start-stop operations
The OPL Series instruments are enclosed in a die cast, weatherproof aluminum case with an optically clear polycarbonate lens. The process connection is available in 1/4 NPT and 1/2 NPT, and you may select either a bronze or a 316 stainless steel bourdon tube sensing element.
Sales Bulletin: OPL/OPLC/OPLFC/OPLFG Series
96001 rev. 2022/09/20
Installation Instructions: OPL/OPLC/OPLFC/OPLFG, 45APE/45APEF Series
00-02-0161 rev. 2023/04/18
The PSB switch is a direct-mount switch for critical pressure points. It has one limit contact that can be used to activate an alarm, actuate indicator lights or shutdown equipment.
The construction of this instrument is the same as Murphy’s time-proven Swichgage instrument. 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 is factory preset according to your specifications.
Housing is weather sealed to prevent entry of moisture, dust, etc. A glass-filled nylon terminal block with screw terminal connections gives the PSB switch a real advantage in industrial engine applications. The PSB is ideal when reading is not desired, but pressure is critical to operational efficiency. Intended for use in general purpose non-classified areas.
Features include:
· Fits all engine applications
· SPDT snap-switch
· Activates indicator lights, alarms or shuts down equipment
· Time-proven Swichgage construction
· Easy wiring terminal block
· Steel housing specially coated to resist corrosion
· Factory preset to your specifications
Sales Bulletin: Model PSB
9104 rev. 2014/10/11
The PD8100 Series eliminates pointer flutter on pressure indicating Swichgage devices which are subject to pulsating pressure from reciprocating pumps or compressors. It also allows a close setting of high and low contact points providing for more accurate pressure indication and control of equipment.
The PD8100 Series decreases wear on geared movements and increases the life of pressure indicating instruments by eliminating excessive gage strain and unnecessary movement, a necessity which quickly pays for itself by protecting any pressure indicating and control instrument which is subject to pulsation.
PD8100 SERIES IS NOT FOR USE ON OXYGEN OR LIQUID OXYGEN APPLICATIONS.
The PD8100 is quality built with a large diameter valve stem wheel for ease of adjustment and features clearly printed operating instructions. Machined from 1 3/8-inch (35 mm) hex bar stock, a two degree taper on the valve and stem assure positive dampening.
It’s available in brass, carbon steel, 303 stainless steel or 316 stainless steel to meet pressure and environmental requirements with either 1/2 NPT or 1/4 NPT inlet connections.
Sales Bulletin: PD8100 Series
95145 rev. 2014/09/27
The Murphy PT167EX is a pressure Swichgage instrument connected to a threaded pressure diaphragm housing. The Swichgage instrument is enclosed in an explosion-proof case and is CSA rated for Class I, Division 1, Groups C and D.
This Swichgage instrument is a pressure-indicating gage with adjustable low and high pressure limit switches. When the gage pointer touches the low or high limit switches, an electrical circuit is completed which can operate alarms and/or shut down equipment.
The 2 NPT, sealed diaphragm housing is attached directly to the Swichgage connection. The diaphragm housing is filled with a silicone fluid so that pressure against the diaphragm causes the Swichgage instrument to respond. The housing seals the Swichgage sensing element from the medium being measured.
Applications include highly viscous liquids such as crude oil on lead line applications. Other applications have included asphalt, sludge, abrasive materials, etc.
Sales Bulletin: Model PT167EX
96107 rev. 2016/08/01
Installation Instructions: Model PT167EX
00-02-0161 rev. 2013/09/17
