Knowledge of multi-stage pumps
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Total series connection, half-series connection, and balance disc clearance of multi-stage pumps
The total amount of movement of the rotor back and forth is the total runout; having the rotor in the middle position corresponds to half of that amount. The gap in the balance disk is usually around 0.1–0.2 mm
After each baffle bolt is tightened, pull the rotor back and forth without installing a balance disc to determine the total series displacement. After installing the balance disc, it becomes a half-string quantity. Regarding the clearance of the balance disc, the factory says it’s not necessary to leave any clearance, but there is a concern that the balance disc and the balance drum might stick together at the moment the pump starts operating; therefore, a clearance of 0.10 mm is generally reserved, and it should not be too large.
Do you have any requirements for the total migration amount and the partial migration amount? That is, what value range is considered normal.
As long as each stage of partition is installed in place, the total series quantity remains fixed, and the partial series quantity is half of the total series quantity; this is the theory behind it.
The total clearance is that without a balance disk; it refers to the clearance between the impeller and the mid-stage guide vanes. The balance disk serves to balance forces and also helps to align the impeller with the center of the guide vane flow channel.