First, when running the dosing system should pay attention to what important matters? A. Dosing pressure B. Stroke frequency C. Suction height D. Altitude E. Corrosive chemicals Second, when the metering pump outlet for atmospheric pressure, there What can be done to improve the pump's repeat metering accuracy? Installing the valve spring on the metering pump discharge valve improves repeat metering accuracy, but the most effective improvement is to install a backpressure valve at the end of the line. Third, how to adjust the back pressure valve? 1. Never exceed the maximum working pressure metering pump. 2. When the dosing pump has pressure on the suction side, the pressure on the discharge side of the pump must be at least 1 bar higher than the pressure on the suction side. Fourth, how to choose the right pulse damper volume? By multiplying the metering capacity (ml) per stroke of the metering pump (ml) by 26, the minimum volume (ml) of the pulsation dampener required to reduce the 90% pulsation can be obtained. How to set the pressure of safety valve? The pressure of safety valve can be adjusted within the range of rated working pressure of metering pump, and it is not allowed to exceed the maximum working pressure of metering pump. The safety valve is designed to prevent over-pressurization of the metering pump. For example, if the maximum working pressure of the metering pump is 3 bar, the relief valve pressure should be set at 3 bar, or lower to ensure proper operation of the metering pump. Overpressure is one of the major causes of dosing pump damage. Sixth, if the delivery of liquid is not water, how to calculate the suction height? The rated suction pump height divided by the proportion of liquid measurement. Seven, under what circumstances with self-irrigation aspirated? 1. The measurement of liquid volatile; 2. The measurement of liquid larger proportion; 3. When the need for higher stroke frequency; 4. The metering pump in high altitude work ; 5. In the field of application requires a larger tank, and rely on the self-priming pump is not feasible. 8. Can you give some advice on the choice of pump head for metering pumps? What problems usually arise when it comes to corrosion of pump heads / seals by chemicals? How should we avoid it? The usual problem when it comes to metering pump heads is the presence of acid, chlorine, fluoride and hydrogen peroxide. Due to the different drug concentration and operating temperature, it is difficult to determine the specific pump head material. When measuring fluoride, we recommend using a Viton® sealed PVC pump head. For most chlorination applications, it is best to use an EPDM sealed NP (plexiglass) pump head. For the hydrogen peroxide mixture can only be measured PTFE PTFE sealed PTFE pump head or stainless steel pump head. The measurement of concentrated hydrochloric acid is usually Viton® sealed plexiglass pump head. Concentrated sulfuric acid can be selected PTFE sealed PTFE pump head. The manufacturer of the chemical gives advice or consult the ProMinent® Chemical Preservation Chart to determine the compatibility of the chemical with the contact material. Nine, when measuring the liquid in the pump head, which factors must be considered? The main factors considered are the liquid viscosity, specific gravity, vapor pressure and temperature.