Double-end mechanical seal
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The pump can operate in both forward and reverse directions; it is equipped with API PLAN 53, and the buffer fluid is connected to the BI BO port of the mechanical seal, in line with the current direction of operation. Now the pump needs to run in reverse; does that mean the BI and BO pipelines need to be swapped?
Whether running forward or in reverse, the pressure in the pump’s sealing chamber remains essentially constant, so it is not necessary to reverse the connection.
Isn’t the dual-machine seal equipped with a pump efficiency ring? That pump efficiency ring has a direction of rotation, and it is the pump efficiency ring that provides the force for the circulation of the buffer solution, right? The direction is reversed; the tubing isn’t changed, so isn’t the buffer flowing in the opposite direction?
This post was last edited by Mechanical Seal_CFVR on 2023-1-14 at 11:17. It is necessary to examine the structural design of the seal, take into account the direction of the inlet and outlet for the isolation fluid, and consider whether there are any requirements regarding the rotation direction of the pump efficiency ring. Low inlet, high outlet; the exit is in the tangential direction.
If the inlet and outlet have requirements regarding the rotation direction of the pump efficiency ring, then reversing it requires swapping the positions of the isolation fluid inlet and outlet; if there are no such requirements, no change is needed. The BI and BO ports of the mechanical seal are arranged horizontally (that is, side by side, not top to bottom). Will some air remain at the top of the mechanical seal and not be able to be expelled? Does this have a significant impact on its operation?
I heard for the first time that pumps can be reversed – is it useful to do so?
It’s best to ask the sealing manufacturer; mechanical seals with a 53 flushing method have spiral pumping rings – is there any requirement regarding the direction of rotation for these?
According to the requirements for mechanical seals, reverse rotation is not allowed.
It is recommended to consult the machine seal manufacturer and the pump manufacturer to determine whether the axial force resulting from reversal meets the pump’s design requirements; it would be best if the manufacturers could confirm this