... seal structure, mechanical seal friction is graphite and tungsten carbide, or packing seal, which are no leakage, long lifespan. Working condition ... .5 Mpa, namely pump inlet pressure+ head is less than or equal to 2.5Mpa, pump static pressure test pressure is 3 ... than or equal to 105 D.C pure water or and the liquid's nature of both physics and chemistry of which are similar ...