First, check the oil level, and it is advisable to fill the oil to the center of the oil mark when the pump is stopped. Too low to the exhaust valve can not act as an oil seal, affecting the degree of vacuum. Too high may cause fuel injection when the atmosphere is started. When operating, the oil level is raised, which is normal. Use a clean vacuum pump oil of the specified grade and add it from the filler hole. After refueling, the screw plug should be screwed on. The oil should be filtered to prevent debris from entering and clogging the oil holes.
Second, the pump can be started once in the atmosphere or under any vacuum. If the pump port is connected to a solenoid valve, it should be operated simultaneously with the pump.
Third, when the ambient temperature is too high, the temperature of the oil rises, the viscosity decreases, and the saturated vapor pressure increases, which causes the ultimate vacuum to decrease, especially the total pressure measured by a thermocouple. The ultimate vacuum can be improved by enhancing ventilation or improving pump performance.
Fourth, check the ultimate vacuum of the pump is based on the compressed mercury vacuum gauge. If the pre-extraction check is completed, the pump temperature will be stable, the pump port and the meter will be directly connected, and the ultimate vacuum will be reached within 30 minutes of operation. The value measured by the total pressure gauge is related to the pump oil and the vacuum gauge and the regulation error. Sometimes the error can be very large and can only be used as a reference.piston-vacuum-pump-process
Fifth, if the relative humidity is high, or the pumped gas contains more condensable steam, after opening the pumped container, the gas ballast valve should be opened, and the gas ballast valve should be closed after 20 to 40 minutes of operation. Before stopping the pump, the open air valve can be unloaded for 30 minutes to extend the life of the pump oil.
Sixth, oil selection: the viscosity of the pump oil affects the starting power and the ultimate vacuum of the pump. When the viscosity is high, the vacuum is favorable, and the starting power is larger. The saturated vapor pressure of the oil at the pump temperature will affect the ultimate pressure of the pump. The lower the better. The viscosity of high-speed vacuum pump oil and 3# diffusion pump oil is larger than that of No. 1 vacuum pump oil, and the saturated vapor pressure is lower than that of No. 1 vacuum pump oil, but the price of 3# diffusion pump oil is higher. The specific oil selected can be selected according to the above description combined with the specific use requirements.what-is-roots-vacuum-pump
没有评论:
发表评论