The problem of the bucket pump not being able to transfer light hydrocarbons
Thread Content
For pumps used for unloading C3C4 light hydrocarbons, bucket pump was chosen due to considerations related to the net positive suction head. During subsequent trial operations, the following issues arose: during unloading, the inlet pressure appeared to be normal, but neither when the outlet pressure valve was opened nor when it was closed did the pressure reach the designed value; moreover, the motor current was significantly low, indicating that the pump was not delivering sufficient flow. At the beginning of unloading, the pressure inside the tank was normal, and the inlet pressure of the pump was also normal, so cavitation should not have occurred. Yet, for some reason, the outlet pressure could not be established, and the low current level suggested that the motor was not generating any power. Is it possible that the pump impeller was in the wrong orientation or that there were other problems?
Quietly ask, has the vapor line of the tank truck been opened? The outlet pressure you mentioned should be around 50% of the head when the valve is closed; once the valve is opened, it should be at least higher than the inlet pressure, which is normal.
You mean that by turning on the outlet valve, the current and pressure don’t change much, right? It is recommended to check the outlet check valve or for any areas where the pipes might be blocked!
Fully fill the pump and vent it; clean the inlet filter; open the inlet wide and slowly open the outlet to establish backpressure
May I ask if the exhaust port of a barrel bag pump is a separate exhaust port installed on the pump body? The pump we use is of the PLAN14+72+76 type, and it does not have a separate exhaust port; the vent used for filling the pump is the 76 torch line. It is presumed that the gases inside the pump were not expelled during the filling process. Have you encountered this situation when filling pumps?
PLAN14 itself serves as a venting function; 72+76 should use dry gas seals!
Remove PLAN14 and give it a try blindly!
The last edit to this post was made by backcat666 on 2018-11-16 at 05:30; both 72 and 76 are located on the non-media side, that is, on the second seal on the atmospheric side； Therefore, 76 cannot exhaust the air from the medium pump ； 14 is actually 11+13 ； On the lower part of the pump body in mechanical seal systems, there is usually a pipeline for connecting to a vent or flare, which is used for venting air from the pump