Correct use of Mechanical Seal
The correct use of mechanical seal is mainly the starting, running and stopping of mechanical seal.
1. Preparation of mechanical seal before starting.
(1) Before starting, the auxiliary seal of mechanical seal should be checked, the cooling system and lubrication system should be installed correctly and blocked.
(2) The material pipeline should be cleaned to prevent rust and impurities from entering the seal cavity.
(3) The static pressure test should be carried out, the test pressure is equal to the pressure, and check whether there is leakage at the end face and seal ring of the mechanical seal and whether the seal end cover is leaking.
(4) Finally, use the hand disk to move the coupling to check whether the shaft rotates easily. If the disc movement is very heavy, check whether the matching size is correct, and try to find out the cause of the well to eliminate the fault.
2. The operation of a mechanical seal includes trial operation and normal operation.
(1) In the trial operation of the seal, the sealing liquid (gas sealing) system is started, the cooling system is started, and the filling medium is guaranteed in the sealing cavity, and then the main seal can be activated for trial operation. During the trial operation, if there is a slight leakage phenomenon at the beginning, it decreases gradually after 1-3 hours, which is the normal process of running-in of the seal end face, if the leakage does not decrease all the time, you need to stop and check. If the machine seal heating is serious or even smoke phenomenon, the specific pressure of the spring is too large, and the pressure of the spring can be properly reduced.
(2) After the normal operation seal has passed the trial operation test, it can be transferred to the normal operation under the operating conditions, that is, heating up and boosting the pressure operation. Heating and increasing pressure can be carried out separately, and the process should be slow. Paying attention to the possible changes in the process of pressure boost (or heating), such as whether the machine parts collide or not, whether the end face is detached. Whether the friction heating is too fast, whether the static ring groove and the anti-transfer pin are detached, check the leakage of the sealing ring and the end surface. If everything is normal, it can be formally put into production and operation.
3. Mechanically sealed parking
When the mechanical seal stops, it should also follow a certain sequence of operation. The main engine should be stopped first, and then the sealing auxiliary system and cooling system should be stopped. If you stop for a long time, the media in the main engine should be discharged clean.