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Water Flow Indicators & Switches


We recommend installing a visual flow indicator on every water circuit to give the operator confirmation, usually by a spinning rotor, that water is flowing.

Use flow indicators without switches when an interrupted supply will not cause damage or when the component has its own coolant alarm. For water-cooled components critical to the vacuum (diffusion pump, turbo pump) or those possibly damaged by flow failure (e-beam source, sputter gun), use a water switch with the indicator. Switch should connect to an alarm or process “kill” button.


In a flow switch, a rotating magnet induces a current in an external coil. The current is sensed and compared to a variable set-point value. If the water flow decreases to a value below the set-point, a relay is de-energized. This arrangement ensures that a stuck rotor carrying the magnet cannot give a false positive flow indication.

Specifications Table

Temperature (°C) 90°C
Pressure Rating (psi) 100
Power 115, 50/60 (VAC, Hz)
Pressure Drop Normal Models: 3" long pipe (same I.D.)
Low Flow Models: 6 psi drop (1 gpm)
(115 VAC or 28 VDC)

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