Avoid complicated inline installation—these flow switches insert into a tee or pipe outlet, so you don’t need to disassemble your pipeline. They have a paddle that’s pushed as your liquid moves through to determine flow. When the paddle reaches a set position determined by the set point, it activates or deactivates equipment. They are single pole, double throw (SPDT) and can either turn one device from off to on (normally open) or on to off (normally closed). They should be mounted vertically into a large-diameter horizontal pipeline, so liquid pushes the paddle.

These flow switches are calibrated with water. You can use them with other liquids, but they may not measure accurately if the liquid’s viscosity differs from water.

Choose a fitting material that is compatible with the liquid you're running through your line.