Special pump factory professional sharing: the cause of gear pump failure and the precautions after shutdown

Gear pump shutdowns are primarily caused by failure of the mechanical seal. The performance of failure is mostly leakage, and the reasons for leakage are as follows:

1 Leakage of the static sealing surface of the static ring, the main reasons are: the flatness of the end face, the roughness does not meet the requirements, or the surface is scratched; there are particulate matter between the end faces, causing the two end faces not to operate in the same way; the installation is not in place, the way is not correct.

2 compensation ring seal leakage, the main reasons are: gland deformation, pre-tightening force is uneven; installation is not correct; the quality of the seal ring does not meet the standard; the seal ring selection is wrong.

The precautions after the gear pump is stopped are as follows:

1 Pumps that are easy to crystallize, easy to solidify, and easy to precipitate, should be blocked after stopping the pump, and flush the pump and pipeline with water or other medium in time.

2 High-temperature pump parking should be carried out according to the provisions of the equipment technical documents. After parking, it should be half-turned every 20 to 30 minutes until the pump temperature drops to 50 °C.

3 After the gear pump stops running, the pump's population valve should be closed. After the pump is cooled, the valve of the auxiliary system is closed. Drain the liquid accumulated in the pump to prevent rust and cracking. Close the valve of the accessory system. Drain the liquid accumulated in the pump to prevent rust and cracking.

4 When the cryopump is parked, when there is no special requirement, the pump should always be filled with liquid; the suction valve and the discharge valve should be kept normally open; the cryopump with double mechanical seal, the liquid level controller and the sealing liquid in the pump seal chamber The pumping pressure of the pump should be maintained.