Submerged slurry pump is a kind of common equipment, which sometimes causes the temperature of equipment to rise because of long running time or improper operation. Once this happens, we must pay attention to it and take cooling measures. Mechanical seal of submersible slurry pump with double end faces: circulating flushing and cooling are adopted, and its service life is 1.5 ~ 2 times that of desulfurization pump with single end face.