P51-Gage

Supported Applications

The P51-Gage series is a stainless-steel pressure transducer built for commercial, industrial, and process-control applications that demand high accuracy and reliability. A bulk micro-machined stainless-steel diaphragm with welded construction gives it the ruggedness needed for demanding pressure monitoring and control loops.

The transducer measures the pressure of air, gases, and liquids that are compatible with 304L or 316L stainless steel. Representative media include:

• Refrigerants, glycol, and water or waste water.
• Motor oil, diesel, hydraulic fluid, and brake fluid.
• Compressed and process gases such as hydrogen, nitrogen, and air.

Because the wetted parts are 304L or 316L stainless steel, the P51 is well suited to HVAC/R, hydraulics, and general fluid-power and process pressure measurement.

Operating Conditions & Performance

The P51 is available in three pressure-sensing types: Gage (PSIG), Sealed Gage (PSIS), and Absolute (PSIA). Accuracy, specified at 22 °C (71.6 °F), depends on the full-scale range: < ±1.0% FS for 15 to 60 PSIG/PSIS ranges and < ±0.5% FS for 75 to 300 PSIG/PSIS ranges, with comparable bands across the sealed-gage and absolute ranges. Response time is < 1 ms.

Electrical operation covers three output options and their supply requirements:

• 4 to 20 mA (2-wire, loop powered), drawing a supply current of 25 mA minimum.
• 0.5 to 4.5 VDC (3-wire), powered from a dedicated 5.00 VDC ±0.500 VDC supply and drawing < 3 mA.
• 1 to 5 VDC (3-wire), drawing < 5 mA.

For the current and 1 to 5 VDC outputs the supply is 8 to 30 VDC with no load; a 4 to 20 mA loop needs 13 to 30 VDC into a 250 Ohm load, or 18 to 30 VDC into a 500 Ohm load. The 4 to 20 mA output drives up to 800 Ohms maximum at 24 VDC.

Environmental and mechanical ratings include:

• Process temperature: −40 to 257 °F (−40 to 125 °C).
• Ambient temperature: −40 to 176 °F (−40 to 80 °C).
• Humidity: 0 to 95% RH, non-condensing.
• Enclosure: NEMA 4 rated.
• Vibration: 100 to 2000 Hz, 20g sinusoidal across 3 axes for 144 hours.

The transducer weighs 0.32 lbs. (0.145 kg), with an overall length of 66.6 mm and a body diameter of 22.23 mm. It is CE, UKCA, RoHS2, WEEE, and ISO 9001 compliant.

Configuration Options

Every P51 is configured through an ordered model-number string of the form P51 – Full Scale Pressure Range – Pressure Units – Port/Fitting Configuration – Connector/Lead Style – Output Signal – Factory Supplied – Factory Supplied. The configured variants therefore differ from one another along several axes:

• Full-scale pressure range: selected in defined steps, for example 100 PSI (689.476 kPa), 200 PSI (1.379 MPa), 300 PSI (2.068 MPa), and 500 PSI (3.447 MPa), scaling from a 3 PSI (20.684 kPa) minimum step up through higher ranges.
• Pressure-sensing type: Gage, Sealed Gage, or Absolute, set by the pressure-units segment of the code.
• Port and fitting configuration: stainless-steel process fittings differing by port style, which also changes the recommended torque.
• Output signal: a voltage output such as 0.5 to 4.5 VDC or 1 to 5 VDC, or the 4 to 20 mA current loop.
• Connector/lead style: a Packard connector, an I24 PVC cable, or an MD Din 43650 connector with a right-angle mating connector.

Recommended installation torque also varies by port: 150 in lb (16.95 Nm) for standard ports, dropping to 120 in lb (13.6 Nm) for port types U and Y, and rising to 300 in lb (33.9 Nm) for high-pressure ports.

Key Product Differences

Representative configured model numbers in the series include:

• P51-100-G-A-P-5V-000-000
• P51-200-G-B-P-4.5V-000-000
• P51-300-A-B-P-5V-000-000
• P51-400-S-B-P-5V-000-000
• P51-500-S-B-P-5V-000-000
• P51-500-S-U-P-20MA-000-000

Available accessories are ordered separately and include Packard wire harnesses in lengths from the A/GP 2' Harness (Item 142606) through the A/GP 40' Harness (Item 136995), stainless-steel snubbers (A/0.25" SNUB A/G, Item 137105, for air and gas; A/0.25" SNUB WTR, Item 137104, for water and light oils), and a GP NIST Calibration Certificate (Item 142927).