20P/25P - FW Murphy Production ControlsFW Murphy Production Controls

Swichgage Series

These 2-inch and 2-1/2 inch pressure gauges feature built-in electrical switches for activating alarms and/or shutting down equipment.

Combination indicating gauge and limit switch
Critial pressure limit switch is visible and adjustable (most models)
Face sealed from environment by unique combination of materials and assembly
Contacts are grounded through the case and have self-cleaning motion to ensure electrical continuity

FW Murphy Production Controls offers support for all our products. If you are unable to find the product that you need, please call us at 918-957-1000.

The 20P Series (2 in./51 mm dial) and the 25P Series (2-1/2 in./64 mm dial) Swichgage 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 are 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 switches, are also available.

Base Models

20P and 25P Series Swichgage
The gauge pointer makes with an adjustable contact to complete a pilot-duty circuit.

20PE Swichgage (was 20EO)
Features internal snap-acting SPDT switches, instead of the single pole/pointer contacts. When the switch closes on falling pressure, it becomes set, as pressure rises the switch resets.

20P7 Lockout Swichgage
Same as 20P Series. It also includes a front, semi-automatic lockout for startup override. This built-in device holds the pointer away from the contact on startup. When pressure exceeds the set point, the lockout is automatically disengaged (see bulletin for details).

Dial: White on black, dual scale;
- U.S.A. standard scale is psi/kPa
- U.K. standard scale is psi/bar
- Others available
Case: Plated steel; mounting clamp included (except for direct mount models)
Bezel: Polished stainless steel, standard
Lens: Polycarbonate, high-impact
Oil: Silicon oil
Process Connection: 1/8-27 NPTM brass
Sensing Element: Beryllium copper diaphragm
Gage Accuracy (% of Full Scale):

RANGE	LOWER 1/4	MIDDLE 1/2	UPPER 1/4
≤300 psi (20 Bar)	±3%	±2%	±3%

Maximum Pressure: See Pressure Ranges and Factory Settings in bulletin
Adjustable Limit Contact (20P and 25P): SPST contact; pilot- duty only, 2 A @ 30 VAC/DC; Normally Close (NC) when the low limit is met. Normally open (NO) when pointer is in normal operating range
- Contacts are gold flashed silver.
Limit Contact Adjustment: By a 1/16 in. hex wrench thru 100% of the scale
Limit Contact Wire Leads: 18 AWG (1.0 mm²) x 12 in. (305 mm)
Snap-Switch Rating (20PE and 25PE): SPDT, 3 A@ 30 VDC inductive; 4 A @ 125 VAC inductive.
Snap-Switch Wire Leads: 20 AWG (0.75 mm²) x 12 in. (305 mm)
Approximate Unit Weight:
- 20 Series: 8 oz. (0.23 kg)
- 25 Series Models: 11 oz. (0.31 kg)
Approximate Unit Dimensions:
- 20 Series: 3 x 3 x 3 in. (76 x 76 x 76 mm)
- 25 Series Models: 4-3/4 x 4-3/4 x 2-3/4 in. (121 x 121 x 70 mm)