Dry gas seal issues in liquefied gas pumps
Thread Content
I have a gentle question: if there is one main liquefied gas pump and one backup pump, and the pumps are equipped with dry gas seals, does the nitrogen valve of the dry gas seal need to be closed when switching between the pumps, that is, after the pump that was in operation stops? If the dry gas seal is not closed, will nitrogen flow from the flow control orifice plate to the vent pipe? Thank you, those who know please let me know
After switching to pump shutdown, the nitrogen valve of the dry gas seal **needs to be closed**. If it is not closed, nitrogen will continue to flow into the sealing chamber through the flow control orifice plate and then be discharged via the vent pipe, which results in waste of nitrogen and may also affect the pressure balance in the sealing chamber. Therefore, it is generally recommended that the nitrogen valve be closed after stopping the pump, and reopened before starting the standby pump. .
It depends on whether it has a single-seal or double-seal design. In the case of a single-seal, turn off the sealing nitrogen first before releasing pressure from the pump; for a double-seal design, there is no need to turn off the sealing nitrogen