Pressure Switches and Sensors
Pressure switches, pressure sensors and pressure transmitters decide at which pressure a pump system starts and stops. This category covers switches, sensors, transmitters and differential pressure sensors for booster, pressure boosting and circulation systems. The category includes products from Danfoss, Telemecanique Sensor, Grundfos and Gama Sensör.
A pressure switch is a mechanical switch. It starts the pump at the set lower pressure and stops it at the upper pressure. It is used in single-pump booster sets and simple systems.
Pressure sensors and pressure transmitters measure pressure continuously and convert it into an electrical signal, usually 4–20 mA or 0–10 V. Speed-controlled pumps, multi-pump booster sets and control panels work with this signal.
A differential pressure sensor measures the pressure difference between two points. It is used to keep a constant differential pressure in circulation systems, to monitor filter clogging and to estimate flow.
When choosing a product, check:
Measuring range: the highest operating pressure should stay well below the top of the range.
Output signal: it must match the input of the controller or pump (4–20 mA, 0–10 V etc.).
Process connection: thread type and size must fit the existing installation (G 1/4, G 1/2 etc.).
Electrical connection and protection class: connector type and IP rating must suit the installation site.
Medium and temperature: the product must suit the liquid (water, water-glycol) and operating temperature.
Frequently asked questions
What is the difference between a pressure switch and a pressure sensor?
A switch only turns on and off. A sensor or transmitter measures pressure continuously and sends the value to a controller, so pump speed can follow the pressure.
How do I replace a faulty switch or sensor?
Enter the part number from the label of the existing product in the search box. If it is unreadable, choose a product with the same measuring range, output signal and connection size.
Should I choose 4–20 mA or 0–10 V?
Check the input of the controller. Over long cable runs and in electrically noisy environments, 4–20 mA is more stable.
Can't find the right product? Send us the part number or pump model and we will help you choose.
