The main components of extra-high boosting mechanism of HJ300 series products adopt imported metal material with high intensity.Their main seal machanism have the function of automatic compensating from outside,which can make the service life of seal components 3 to 4 times of ordinary one during working.Integrated one-way value is adopted in inlet and outlet,which decreases the number of seal nozzles and then prolongs service life of pump seat.because optimized design is adopted in the whole machine,pure mechanical boosting make installation and maintenance convenient and easy.