Analysis of an end face mechanical seal with internal valving for low power applications

Certain end face mechanical seal geometries are utilized with internal valving ports machined into their faces that create a complex sealing requirement from the high pressure at some of the ports to low pressure (typically atmospheric) at both the seal OD and ID and intermediate or atmospheric pressures at other ports. During operation, friction is generated between the surfaces causing power loss from the system. In low power applications, friction from the mechanical seal can greatly reduce the effectiveness of the system and therefore the seal requires much needed component consideration to reduce the power loss. In this presentation, one such seal is discussed including the surface roughness and geometrical properties, material selection, face pressure, and other components to reduce the power loss of the seal and stay within an acceptable leakage limit. Analysis of the seal surfaces and materials is accomplished using white light interferometry, SEM, and EDS.