Common faults of screw pumps and their solutions
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Serial Number Fault Phenomenon Cause Solution 1 Pump fails to draw in oil (1) Blockage or air leakage in the suction pipeline (2) Suction height exceeds the allowable vacuum level (3) Motor rotates in the reverse direction (4) Medium viscosity is too high (1) Repair the suction pipeline (2) Reduce the suction height (3) Reverse the motor’s rotation (4) Heat the medium 2 Large fluctuations in the pressure gauge reading (1) Air leakage in the suction pipeline (2) Safety valve not properly adjusted or operating pressure too high, causing it to open and close frequently (1) Repair the suction pipeline (2) Adjust the safety valve or reduce the operating pressure 3 Decreased flow rate (1) Blockage or air leakage in the suction pipeline (2) Wear on the screw and pump casing (3) Safety valve spring is too loose or the valve disc does not seal properly against the seat (4) Motor speed is insufficient (1) Repair the suction pipeline (2) Replace worn parts when necessary (3) Adjust the spring and polish the valve disc and seat (4) Repair or replace the motor 4 Sudden increase in shaft power (1) Blockage in the discharge pipeline (2) Severe friction between the screw and pump casing (3) Medium viscosity is too high (1) Stop the pump and clean the pipeline (2) Repair or replace relevant parts (3) Heat the medium 5 Excessive vibration of the pump (1) Pump and motor are not aligned (2) Screw and pump casing are not aligned or there is excessive clearance (3) Air present inside the pump (4) Excessive installation height, resulting in cavitation inside the pump (1) Adjust alignment (2) Perform repairs and adjustments (3) Repair the suction pipeline to eliminate air leaks (4) Reduce installation height or lower speed 6 Pump overheats (1) Severe friction inside the pump (2) Blockage in the oil return hole of the mechanical seal (3) Oil temperature is too high (1) Inspect and adjust the screw and pump casing (2) Clear the oil return hole (3) Lower the oil temperature appropriately 7 Severe oil leakage from the mechanical seal (1) Incorrect installation position (2) Seal gland not pressed tightly enough (3) Damage to the dynamic or static seal ring (1) Reinstall according to specifications (2) Adjust the seal gland (3) Polish the seal surfaces or replace with new parts (4) Replace the seal ring
Thank you, OP; I look forward to more exchanges if there’s a chance
The original poster has summarized it perfectly. Incidentally, here is some knowledge excerpted from other sources for everyone’s learning and discussion: 1. Installation requirements for SM and SN type triple-screw pumps. 1. Before installing the triple-screw pump, check whether its oil seals are in good condition, and also verify whether the pump has been damaged during transportation. You can manually rotate the coupling to see if there is any resistance; if so, the pump should be disassembled for cleaning, repair, and adjustment. 2. When installing the inlet and outlet pipes for the triple-screw pump, their diameters must not be smaller than those of the pump’s inlet and outlet ports. The inlet pipe should not be too long, nor should there be too many bends, as this will affect the pump’s performance. 3 When two or more triple-screw pumps are installed on the same pipeline, a check valve must be installed on the oil discharge pipe leading to the pumps in order to facilitate their startup. 4. For standby pumps used to transport oils with high viscosity at higher temperatures (above 60°C), such as heavy oil, they must be heat-ready standby pumps; otherwise, starting the pump at low temperatures can cause the motor to overload or damage the pump. 5. The pump should not be started when there is no liquid in it or when the outlet valve is fully closed – the pump must be filled with the liquid to be transported before it is started ； 6. When the temperature of the liquid being transported is above 60°C, preheating shall be carried out in accordance with the provisions in the equipment’s technical documents ； 7. During the trial run, it is also necessary to check whether the safety valve is sensitive and reliable.
Great, if we study*, we’ll have the chance to communicate more.
Could someone with expertise please explain the nameplate of the snh/c660r46um3nw21 screw pump?
It’s just the explanation given in the screw pump manual; let’s discuss whether there is any specific knowledge regarding maintenance