The 20DP and A20DP Series (2 inch/51 mm dial) and the 25DP and A25DP Series (2-1/2 inch/64 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 and 25DP series mechanism is enclosed in a steel case coated to resist corrosion. The A20DP and A25DP series have 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.
- Constant visual indication of the condition of your filter is shown on the dial.
- Two instruments in one with an accurate indicating gage and adjustable p.s.i.d. limit switch reduces inventory and installation time.
- Adjustable contact lets you set the monitoring range of the gage. The contact is tamper proof and can be set only with a 1/16 Allen-head wrench.
- All gages are made of durable materials allowing them to withstand rugged applications.
- Early filter changes cost you money and increase the risk of contaminants entering the system. A Murphy filter restriction Swichgage instrument will let you know when to change the filter and maintain peak efficiency.
20DP, 25DP, A20DP and A25DP Swichgage instrument
The gage pointer makes with an adjustable contact to complete a pilot-duty circuit.
20DPE, 25DPE, A20DPE and A25DPE Swichgage instrument
20DPE (was 20DPEO), 25DPE (was 25DPEO), A20DPE (was A20DPEO) and A25DPE (was A25DPEO).
Features an internal snap-acting SPDT switch, instead of the single pole/pointer contacts. When the switch closes on rising pressure, it becomes set, as pressure falls the switch resets. 20DPG, 25DPG, A20DPG and A25DPG Murphygage instrument gage without contact(s).
Dial: White on black, dual scale; U.S.A. standard scale is psi/kPa. Other scales available
Case: 20DP and 25DP Series: plated steel. A20DP and A25DP Series: polycarbonate
Bezel: Polished stainless steel, standard; others are available.
Lens: Polycarbonate, high-impact
- Ambient: -40° to 150° F (-40° to 66° C)
- Process: -40° to 250° F (-40° to 121° C)
Process Connection: 1/8-27 NPTM brass
Sensing Element: Beryllium copper diaphragm
Gage Accuracy: ±3% maximum across scale
Snap-Switch Rating (DPE models): SPDT, 3 A @ 30 VDC inductive; 4 A @ 125 VAC inductive
Adjustable Limit Contact: SPST contact; pilot duty only, 2 A @ 30 VAC/DC; closed when the low limit is met, open when pointer is in normal operating range. Contacts are gold flashed silver.
- Limit Contact Adjustment: by 1/16 in. hex wrench through 100% of scale.
- Limit Contact Wire Leads (20DP and 25DP Series): 18 AWG (1.0 mm2) x 12 in. (305 mm)
- Limit Contact Terminals: A20DP Series #4 screw terminals. A25DP Series #6 screw terminals
Unit Weight: 20DP and A20DP Series: 9 oz. (0.25 kg); 25DP and A25DP Series: 11 oz. (0.29 kg)
- 20DP and A20DP Series: 3 x 2-3/4 x 2-3/4 in. (76 x 70 x 70 mm).
- 25DP and A25DP Series: 4-3/4 x 4-3/4 x 2-3/4 in. (121 x 121 x 70 mm)
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