In addition to the characteristics of general reciprocating pump, the reciprocating cryogenic liquid pump should pay special attention to the characteristics of its cryogenic liquid pump.
The flow of the reciprocating cryo liquid pump is related to the diameter D of the cylinder sleeve, the piston stroke S, the rotational speed of the pump (the reciprocating number of piston or plunger N) and the sealing characteristics. The relationship between pump lift (or discharge pressure) is small (volumetric characteristics).
The performance curve of the reciprocating cryogenic liquid pump is basically a vertical line, and only when the pressure is high, the increase in leakage in the sealing part will reduce the flow. Reciprocating cryogenic liquid pump is, therefore, cannot be used on the exhaust pipe of the valve to regulate flow, this is totally different from the centrifugal pump at low temperature, so the piping layout and operation must be fully note that never closed the valve on the liquid on the discharge pipe die! Otherwise it will damage the pump and even cause an accident. To avoid misoperation, set the safety valve or other safety device before the globe valve, or set the check valve only. The cut-off valve on the pump discharge line must normally open during normal operation.
The lift (or discharge pressure) of the reciprocating cryogenic liquid pump is affected by the system force. As long as the original motive power is sufficient, the transmission box and the transmission mechanism are rich in strength, and when the sealing performance is good, the discharge pressure can meet the needs of different devices. For example, the discharge pressure of reciprocating cryogenic liquid pump in the process of filling the bottle also changes from 1MPa to 14.7mpa from the remaining pressure in the bottle.
The hydraulic end (pump head) is working under extremely low temperature conditions, and the incoming of heat will have a bad effect, so we should do a good job of insulation work, pay close attention to the sealing of the joints and prevent leakage. The materials used should be suitable for working at low temperature and have certain requirements for anti-corrosion. To prevent foreign bodies from entering.