Mechanical seal technology is a sum of mechanical engineering and material physical property technology and the core technology is mechanical seal material tribology(friction,wear and lubrication etc.). it is important and helpful to know the friction PV value of different material combinations at different temperatures,pressures,fluids and rotating speeds. Ningbo Donglian Mechanical seal Co.,Ltd, is researching and studying on the methods of measuring the friction PV values of different material faces/rings:silicon carbide,ceramic,tungsten carbide and carbon. Mechanical seals are organized with many seal face combinations:pressureless sintered silicon carbide(ssic)/carbon(M106F),sintered silicon carbide(ssic)/antimony carbon,silicon carbde(sic)/carbon(M106K),ceramic/carbon(M106F),tungsten carbide/silicon carbide,tungsten carbide/tungsten carbide,pressureless silicon carbide/pressureless silicon carbide,304/carbon(M106K),silicon carbide/tungsten carbide. the friction PV value is helpful to select the right materails as mechanical seal rings/faces especially mechanical seals are used to prevent the dangerous fluids or toxic fluids from leaking.