Metering pump is a kind of special positive displacement pump that can meet the needs of various strict processes, and the flow rate can be adjusted stepless in the range of 0-99% for the transportation of liquids (especially corrosive liquids). Metering pump is also known as quantitative pump or proportional pump, metering pump is a reciprocating positive displacement pump, for accurate measurement, the general requirements of the stable accuracy of the metering pump is not more than ±1%. With the continuous development of modern industry towards automated operation and long-distance automatic control, the advantages of strong compatibility and wide adaptation to the medium (liquid) are particularly prominent.

Metering pump construction 

The hydraulic metering pump consists of three parts: motor, gear box and cylinder block. The gear box is composed of worm mechanism, stroke adjusting mechanism and crank connecting rod mechanism. By turning the adjusting handwheel to implement the high adjustment stroke, and then change the eccentricity of the moving shaft to achieve the purpose of changing the plunger (piston) stroke. The cylinder block components are composed of a pump head, an intake valve group, an discharge valve group, a plunger and a rotary seal.

Working principle of metering pump

The motor drives the worm through the shaft connecting device and reduces the speed of the worm wheel to make the spindle and eccentric wheel rotate, and the eccentric wheel pushes the rolling adjusting seat of the arch connecting rod to make repeated movement. When the plunger moves back to the dead point, a vacuum is gradually formed in the pump chamber, and the suction valve is opened to suck in the liquid; When the plunger moves to the forward dead point, the suction valve is closed, the discharge valve is opened, and the liquid is discharged when the plunger moves further. The reciprocating operation of the pump also produces a continuous pressure, quantitative discharge liquid.

Hydraulic metering pump flow regulation

The flow regulation of the pump depends on the rotation of the regulating handwheel and the rotation of the regulating screw, so as to change the spacing between the arch connecting rod and change the piston (piston) to move the stroke in the pump chamber to determine the size of the flow. Adjusting the scale of the handwheel determines the plunger stroke with 95% accuracy.

Hydraulic metering pump installation

1. Exports are higher than imports to prevent siphoning

2. The pump head and injection valve must be installed vertically

3. Tighten the attached pipe fittings with your hands, do not use tools; Do not use raw tape on thread

4. The supply voltage is stable and grounded

5. The installation environment is clean and spacious with good ventilation.