PR‑23‑W Saunders® valve body flow cell can be mounted either vertically or horizontally. Special sensor support is not needed as the valve body (piping) supports the sensor. Either way sensor cover must always be horizontal to avoid sedimentation or gas/air pocket on the prism. Also installation after pump, before valve and low installation point reduces risk of air/gas pocket. Recommended flow velocity is 1.5 … 6 m/s (5 … 20 ft/s).