whether the pump is running or not, the meter metering pump can adjust the flow within the range of -1%; 1% steady-state repeatability; It can provide pump heads made of various materials such as PP, PVC, PVDF, 316 stainless steel, Alloy2 alloy, Hastelloy alloy and cast iron, and diaphragms made of various materials such as PTFE/ composite rubber, Teflon/ composite rubber, stainless steel and alloy, which can meet the requirements of different technological processes and meet the requirements of various control systems. High-performance diaphragm pump head uses the patented MARS technology (automatic mechanical oil replenishment system) of Mi Dunluo Company, which integrates the advantages of various traditional pump heads. The high-performance diaphragm pump head cancels the disc diaphragm guard plate at the material end required by the traditional hydraulic pump head, so that the pump head has both the "direct passability" of the tubular diaphragm and the low NPSH (net positive suction head) requirement of the piston pump.