How to put into use the cascade seal (P23+P53A) for the slurry pump? What is the specific plan?
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This post was last edited by 156026692 on 2018-10-30 at 13:21. I have a question regarding the operation of the seals for the catalytic slurry pumps: For our catalytic units, the seal configuration used for the two slurry pumps is P32+P53A. The inlet pressure of these pumps is 0.2 MPa, while the normal operating outlet pressure is 1.8 MPa. The oil for the first seal is supplied by a diesel pump, with a maximum pressure of 2.4 MPa. The second seal uses TSA46 turbine oil, and the nitrogen pipeline at the top of the sealing tank draws pressure from a nitrogen tank, with a maximum pressure of 2.0 MPa. Question: The instructions regarding the sealing of the slurry pump are not particularly clear or explicit, so it is necessary to develop additional procedures for the sealing of this pump. Could you provide specific operational guidelines or approaches? The more detailed, the better – for example, which seal should be activated first when starting the pump, what should be the specific pressure for the sealing oil, and what should be the nitrogen pressure? ）!
Correction: the sealing solution is P32+P53A, apologies
Both seals must be in use before starting the pump. The pressure ratio of p32 is 0.1–0.2 MPa higher than that of the seal chamber, while p53a has a seal oil pressure that is 0.2–0.3 MPa higher than that of the first stage. Start up the warm pump, exhaust pump, liquid discharge pump, and disc pump!
This post was last edited by 3983596_FPPZ on 2018-10-30 08:19. Thank you to this member for paying attention to this section and actively participating; getting up so early to post replies is really appreciated
How is the pressure in the machine seal chamber determined?
The pressure in the mechanical seal chamber can only be determined by consulting the manufacturer; it is usually an empirical value. For single-stage cantilever centrifugal pumps, a pressure of around inlet pressure + 0.1 MPa is generally used
Okay, thank you. I’ll ask the manufacturer for their recommended pressure later
Close the inlet and outlet valves of the standby pump as well as the pre-heating valve, stop the seal oil injection, and check the reading on the seal oil injection (PLAN32) pressure gauge to see if it is possible to measure the pressure on the medium side of the pump. If possible, the pressure at this point would be approximately the pressure in the sealed chamber. The pressure of the seal oil injection (PLAN32) must be higher than the pressure in the sealing chamber to ensure that the seal oil can be injected. The pressure of PLAN53a is 0.1-0.2 MPa higher than that of PLAN32. In other words, the first seal is used to seal the medium, preventing it from leaking into the atmosphere ； The second seal is made of sealing oil, which prevents this oil from leaking into the atmosphere; and in the event of a leak, it can only be white oil (TSA46 turbine oil) that leaks into the sealing chamber and then moves along with the fluid. When it is necessary to top up the lubricant frequently, that means the seal is leaking.
Diesel used for P32 sealing is inappropriate as it tends to vaporize and cause vacuum; reprocessed oil can be used instead!
This issue does exist, but the process has not been changed yet. Will impurities in the reprocessed oil affect the operation of the seal?
First, install the outer mechanical seal p53a, then the inner one p32