Reciprocating Pump Valve Design

Lecturepg. 39The working mechanism and life expectancy of automatic pump check valves, which are important for the operational safety of oscillating displacement pumps, are closely examined. A calculation process for the determination of the valve kinematic and pressure losses is discussed, which is based on hydrodynamic coefficients. These coefficients are dependent on the Reynolds number. It also is based on the force equilibrium exerted on the active valve body. It is shown that a numerical calculation can correctly determine closing delay, closing speed and valve pressure losses for Newtonian liquids. A design strategy is shown for the prognosis of life expectancy of automatic check valves. It is based on the tribometric simulation in a tamping tribometer. Field tests have shown that the tribometric simulation is close to reality. However, the tribosystem must necessarily be operated in its stable range to eliminate radial erosion. In addition to the relative hardness of the construction material or to the abrasive particles, the SAR-Number, which should be smaller than 90-100, is an important indicator. The investigations are a substantial contribution to the design improvement of automatic pump check valves