Refer to the Mounting notes and Commissioning notes.

Note the correct direction of flow, for both two-port and three-port valves, as shown in the diagrams below.


Fit a strainer upstream of the valve to increase reliability.


The direction of flow for two-port valve MUST be as indicated by the arrow, from A → B.

MVI422…two-port valve

De-energized position: Port “A” closed

Three-port valves can be used in both diverting and mixing circuits.

When used in diverting circuits, the direction of flow for three-port valve is as indicated by the arrow in the valve body, from AB → B and AB → A (recommended) .

When used in mixing circuits, the direction of flow for three-port valves is opposite the arrow in valve body, from A → AB and B → AB.

MXI422…three-port valve (diverting circuits)

MXI422…three-port valve (mixing circuits)

De-energized position: Port “A” closed

De-energized position: Port “A” closed