PX309 - Stainless Steel Pressure Transducer 5000 psi | Omega Engineering
MPN: PX309 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $425 | $425.00 |
| 10 | $395 | $3,950.00 |
| 100 | $360 | $36,000.00 |
| 500 | $330 | $165,000.00 |
| 1,000 | $305 | $305,000.00 |
PX309 Overview
A pressure transducer (also called a pressure transmitter) is an electromechanical sensor that converts an applied fluid or gas pressure into a proportional electrical signal for monitoring, control, or data acquisition. Within the broader sensor taxonomy it sits as: pressure sensor -> transducer -> industrial sensor -> measurement instrument. The 4-20 mA current-loop output is the dominant industrial standard because it is intrinsically safe over long cable runs and is immune to voltage drop on the wiring.
Key features include 0.25 percent or 0.5 percent accuracy classes, long-term stability with low drift, an operating temperature range suited to process environments, and 316L stainless-steel wetted materials compatible with a wide range of media. The series spans gauge, absolute, compound-gauge, and vacuum pressure types, with selectable pressure ranges from a few psi up to 10,000 psi, making it a versatile workhorse for general-purpose industrial use.
The PX309 below 100 psi uses an oil-filled isolation diaphragm that protects the silicon sensing element, while 100 psi and above units bond strain gages molecularly to the diaphragm directly. The all-welded stainless-steel construction provides excellent media compatibility and corrosion resistance, which is critical in hydraulic, chemical, and oil-and-gas applications where aggressive fluids would attack alternative elastomer-sealed sensors.
Typical applications include HVAC system pressure monitoring, hydraulic system pressure feedback, process-control loops in chemical plants, pump and compressor monitoring, water and wastewater treatment pressure measurement, and factory-automation panels.
When wiring this transmitter, supply 12 to 30 Vdc loop excitation, route the cable away from VFD inverters and large motors to minimize EMI, and use a 250-ohm sense resistor across the receiver input to convert 4-20 mA to 1-5 Vdc for older analog-input cards.
This page synthesizes distributor pricing, application guidance, and a comparison with cross-brand alternatives that is not available in the stock Omega datasheet alone.
Drop-in alternatives for PX309 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PX309-100GI
✅ Drop-In📋 Reference alternative (not in catalog)
PX309-2KGI
✅ Drop-In📋 Reference alternative (not in catalog)
PX309-10KG5V
✅ Drop-In📋 Reference alternative (not in catalog)
PX319-5KGI
✅ Drop-In📋 Reference alternative (not in catalog)
MLH05KPGB01B
✅ Drop-In📋 Reference alternative (not in catalog)
PX329-3KG5V
✅ Drop-In📋 Reference alternative (not in catalog)
PX309 Maximum Ratings & Electrical Characteristics
| Manufacturer | Omega Engineering |
| Series | PX309 Stainless Steel Pressure Transducer |
| Pressure Type | Gauge (compound, absolute, vacuum options in series) |
| Operating Pressure Range (this variant) | 0 psi to 5000 psi |
| Maximum Pressure Range (series) | Up to 10,000 psi |
| Output Signal | 4-20 mA (current loop), also available 0-5 Vdc / 0-10 Vdc in series |
| Accuracy | ±0.25% or ±0.5% (model dependent) |
| Sensor Technology | Silicon strain gage molecularly bonded to stainless steel diaphragm (>=100 psi); oil-filled silicon sensor (<100 psi) |
| Wetted Materials | 316L Stainless Steel |
| Process Connection | 1/4 inch NPT Male (model dependent, 1/4 NPT and others in series) |
| Housing | All stainless steel, cylindrical threaded body |
| Supply Voltage (4-20 mA) | 12 Vdc to 30 Vdc |
| Long-Term Stability | Low drift (per series datasheet) |
| Mounting Type | Threaded process mount with inline cable or connector termination |
| Termination (series options) | Cable, mini DIN, twist-lock 6-pin, Packard (model dependent) |
PX309 standard Pin Configuration Guide
Pin configuration for PX309 (standard package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for PX309.
Refer to the datasheet for full pin configuration.
Typical Applications
PX309 is suitable for 7 applications: HVAC Pressure Monitoring, Hydraulic System Pressure Feedback, Process Control in Chemical Plants, Pump and Compressor Monitoring, Water and Wastewater Treatment, Factory Automation and Machine Monitoring, Oil and Gas Industrial Pressure Monitoring.
HVAC Pressure Monitoring
The PX309-5KGI is well suited for HVAC duct and chilled-water pressure monitoring, where it provides a 4-20 mA signal directly to a building automation system (BAS) controller. Its 316L stainless-steel construction handles condensate and glycol mixtures without corrosion, and the 1/4 NPT process connection accepts standard pneumatic and hydraulic tapping fittings. Compared to media-isolated polymer sensors, the all-metal wetted path resists biofouling in closed-loop hydronic systems, making it ideal for hospital and laboratory HVAC loops. The 0.25% accuracy class delivers reliable dp/dt trending for filter-loading diagnostics.
Recommended
Hydraulic System Pressure Feedback
The PX309-5KGI provides 5000 psi gauge feedback for hydraulic presses, injection molding machines, and mobile equipment. Its molecularly bonded strain-gage diaphragm tolerates the dynamic pressure spikes of hydraulic cylinders and pumps, with long-term stability suitable for closed-loop proportional valve control. The 4-20 mA loop output integrates directly to PLC analog input modules over long cable runs typical of factory-floor machinery, where voltage-output sensors would suffer from noise pickup and IR drop. Stainless-steel wetted materials handle petroleum-based hydraulic oils, and the rugged cylinder housing survives mechanical vibration in mobile equipment bays.
Recommended
Process Control in Chemical Plants
In chemical reactors and separator vessels, the PX309-5KGI delivers reliable pressure telemetry for SCADA/DCS control loops, with 4-20 mA intrinsically safe transmission over long runs to control rooms. Its 316L stainless-steel wetted materials resist attack from mild acids, caustics, and organic solvents commonly encountered in batch chemical processes, where elastomer-sealed sensors fail prematurely. The 0.25% accuracy option supports tight control bands for reactor pressure regulation, while the all-welded construction eliminates gasket leak paths. Cable-terminated or twist-lock connector options allow field replacement without breaking the process piping, minimizing plant downtime during calibration cycles.
Recommended
Pump and Compressor Monitoring
Centrifugal pumps, positive-displacement pumps, and reciprocating compressors require continuous discharge-pressure monitoring to detect cavitation, seal degradation, and overload conditions. The PX309-5KGI provides a robust 5000 psi feedback that integrates to VFD-driven pump controllers for closed-loop pressure regulation. Its all-stainless-steel diaphragm tolerates the vibration and pressure pulsation inherent in reciprocating compressor service, where lesser sensors with elastomer diaphragms would fatigue and drift. The 4-20 mA current-loop output maintains signal integrity along motor-room cable trays even in the presence of VFD common-mode noise.
Recommended
Water and Wastewater Treatment
In municipal water treatment and wastewater plants, the PX309-5KGI monitors filter inlet pressure, backwash differential pressure, and treated-water distribution line pressure for SCADA telemetry. The 316L stainless-steel wetted path handles chlorinated and treated water without corrosion, supporting long deployment cycles in remote pump stations. Its loop-powered 4-20 mA output is ideal for solar-powered telemetry in off-grid lift stations where power budget is constrained. The NPT process connection accepts standard brass or stainless tapping saddles used in water utility construction, simplifying retrofit into existing infrastructure.
Recommended
Factory Automation and Machine Monitoring
On automated production lines, the PX309-5KGI provides pneumatic and hydraulic pressure feedback to PLCs for predictive maintenance and process qualification. Its 4-20 mA output integrates with industrial analog input cards over standard shielded twisted-pair cable, supporting centralized monitoring of machine health dashboards. The stainless-steel construction survives wash-down environments in food and beverage facilities where polymer-housed sensors degrade. The 0.5% accuracy class is the cost-optimized choice for general OEE tracking, while the 0.25% class supports calibration-critical applications such as pharmaceutical filling and packaging.
Recommended
Oil and Gas Industrial Pressure Monitoring
In upstream wellhead monitoring skids and downstream refinery service, the PX309-5KGI provides 5000 psi wellhead pressure telemetry for SCADA and remote terminal units. Its all-stainless-steel 316L construction tolerates sour-service exposure (mild H2S) when used with the correct NACE MR0175 compliance option, and the rugged cylinder housing withstands harsh weather exposure in desert or offshore platform environments. The 4-20 mA loop output supports long cable runs from remote well pads to control rooms without signal degradation. Verification of calibration before deployment is essential; the 0.25% accuracy class supports fiscal-metering applications where measurement uncertainty directly affects billing.
Recommended
Recommended Products Summary
Engineering reference data for PX309 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PX309-100GI | PX309-2KGI | PX309-10KG5V | PX319-5KGI | MLH05KPGB01B |
|---|---|---|---|---|---|---|
| Brand | Omega | Omega | Omega | Omega | Omega | Honeywell |
| Package | 1/4 NPT Cylinder Threaded | 1/4 NPT Cylinder Threaded | 1/4 NPT Cylinder Threaded | 1/4 NPT Cylinder Threaded | 1/4 NPT Cylinder Threaded | 1/4 NPT Cylinder Threaded |
| Pressure Range | 0-5000 psi gauge | 0-100 psi gauge | 0-2000 psi gauge | 0-10000 psi gauge | 0-5000 psi gauge | 0-5000 psi gauge |
| Output Signal | 4-20 mA | 4-20 mA | 4-20 mA | 0-5 Vdc | 4-20 mA | 4-20 mA / ratiometric |
| Accuracy Class | ±0.25% or ±0.5% (option) | ±0.25% or ±0.5% | ±0.25% or ±0.5% | ±0.25% or ±0.5% | ±0.1% (higher grade) | ±0.25% (typical) |
| Wetted Material | 316L Stainless Steel | 316L Stainless Steel | 316L Stainless Steel | 316L Stainless Steel | 316L Stainless Steel | Stainless Steel |
| Supply Voltage | 12-30 Vdc loop | 12-30 Vdc loop | 12-30 Vdc loop | 12-30 Vdc (voltage output) | 12-30 Vdc loop | 5 Vdc / 6-30 Vdc (variant dependent) |
| Sensor Technology | Silicon strain gage bonded | Silicon oil-filled diaphragm | Silicon strain gage bonded | Silicon strain gage bonded | Silicon strain gage bonded (higher precision) | Silicon piezoresistive (Honeywell ASIC) |
| Process Connection | 1/4 inch NPT Male | 1/4 inch NPT Male | 1/4 inch NPT Male | 1/4 inch NPT Male | 1/4 inch NPT Male | 1/4 inch NPT Male |
Key Differentiators
- All 316L stainless-steel construction across full pressure range (vs MLH05KPGB01B)
- Higher accuracy option at 0.25% with better temperature stability (vs PX309 vs. PX309-10KG5V (voltage output))
- Wider range of pressure options within the same mechanical family (vs MLH05KPGB01B)
Design Notes
The 4-20 mA current-loop variant of the PX309 requires 12 to 30 Vdc loop excitation. The receiver side typically includes a 250 ohm precision sense resistor to convert 4-20 mA to 1-5 Vdc for legacy analog input cards. Estimate that a 24 Vdc supply can support up to 600 ohm total loop resistance (including cable IR drop) - for cable runs over 500 m, calculate the cable resistance and budget voltage headroom to ensure at least 12 Vdc remains at the transmitter under all conditions.
Mount the PX309 with the process tap at the side or top of the pipe to prevent sediment accumulation in the sensor cavity. Use a pressure-snubber or siphon loop for steam service to protect the diaphragm from thermal shock. For high-vibration machinery, use a flexible capillary or mini siphon to isolate the sensor body from vibration. Route signal cable in conduit at least 30 cm from VFD motor cables and cross motor conduits at 90 degrees to minimize common-mode noise coupling into the 4-20 mA loop.
Do not exceed the published proof pressure (typically 2x range) or burst pressure (typically 5x range) - surge spikes in hydraulic systems can quickly exceed rated pressure even when the pump is sized nominally for the rated maximum. Apply thread sealant rated for stainless steel (such as PTFE tape) on NPT connections, but do not use liquid anaerobic sealants that may migrate into the diaphragm cavity. Verify polarity at the termination before applying loop power - reversed polarity will not damage the sensor but produces zero output, leading to confusing troubleshooting.
Compliance Information
Detailed RoHS/REACH compliance not surfaced in the Omega distributor product page; contact Omega for documentation. Not subject to AEC-Q100 (industrial sensor, not automotive). All-stainless-steel construction is intrinsically lead-free and halogen-free but specific declarations are not in the web data.
