Profile: The seal has a profile to it and permits a 1/two or total flip in the pressure gauges readout to be sure correct installation orientation. Profile seals can possibly be external or internally centered. The working basic principle pressure gauge with diaphragm is shown in Figure 1 dependant on https://gastonb049els1.ageeksblog.com/32033490/bourdon-pressure-gauge-can-be-fun-for-anyone