Why must Dwyer pressure switches be mounted with the diaphragm in the vertical plane?
A. In other than a vertical plane, the diaphragm can sag and cause a shift in set-point or a change in the adjustable set-point range. The switch may even fail to reset at the minimum set-points. This is the same phenomena that causes inaccuracy in Magnehelic® and Capsuhelic® gages when mounted in other than a vertical position.