Pressure Transmitter for Water & Wastewater

Define the pressure range first

Choose a range where normal operating pressure sits around the middle of the span. A transmitter that runs near the top of its range has less margin for pressure spikes; one that runs too low loses resolution.

For water and wastewater, common measurements include:

Pump discharge pressure
Filter differential pressure
Tank level (hydrostatic pressure)
Pipeline pressure
Blower and compressor pressure

Check the maximum pressure and surge conditions, not just the normal operating point. Overpressure and burst ratings matter on pump systems.

Gauge, absolute or differential?

Gauge: referenced to atmosphere; the usual choice for pump and pipe pressure.
Absolute: referenced to vacuum; used where barometric changes matter.
Differential: for filter and flow measurement; requires two ports.

Most water and wastewater pressure transmitters are gauge or differential.

Output signal

4–20 mA: the standard for long cables and PLC/DCS inputs.
0–10 V: common in compact OEM and HVAC panels.
RS485 Modbus: useful for digital networks and multi-drop installations.

Use our 4–20 mA calculator to check the current at a given pressure.

Wetted material and connection

316L stainless steel is the standard wetted material for water and wastewater. Confirm the process connection (G1/4, G1/2, 1/4 NPT, 1/2 NPT), the seal material and the cable entry. For dirty water or sludge, a flush diaphragm or a larger port may be easier to clean.

Environment and protection

IP rating: confirm the enclosure protection for washdown or outdoor installation.
Condensation: use a cable gland and installation that keeps water away from the electronics.
Surge: pump systems can generate voltage spikes; use surge protection where needed.
Temperature: check both the medium and ambient temperature.

Installation tips

Install downstream of the pump where flow is stable.
Use a isolation valve and a drain point for maintenance.
Avoid mounting at the bottom of a tank where sediment collects.
Keep the cable away from VFD output cables.

Ordering checklist

Pressure range and overpressure
Gauge, absolute or differential
Output: 4–20 mA, 0–10 V or RS485
Process connection and seal
Wetted material
IP rating and cable length
Calibration certificate required?

See our pressure transmitters for compact, sanitary, high-temperature and display versions, or contact us with the range and connection.