DY155C mechanical seals are found to be used in water pumps,circulation pumps,centrigfugal pumps etc and please take into consideration:the temperature,the pressure and the speed of pump shaft as follows:temperature:-20ºC~200ºC, ≤0.8Mpa and ≤ 10 m/Sec. the face materials are ceramic,carbon,silicon carbide and tungsten carbide etc.