Hale Q Series Muscle - Manual (Page 22)

 Introduction
22 MUSCLE (Midship) Pumps Installation, Operation, and Maintenance Manual
p/n: 029-0020-63-0
Water enters the suction channels on both sides of the impeller, thereby maintaining
axial balance. Dual cutwaters
1
on the Qmax and Qmid strip water from the rotating
impeller and direct it to the discharge path. Radial hydraulic balance in the Qmax,
Qmid, and Qtwo is maintained by the opposed discharge volute cutwaters.
The Qflo, Qflo Plus, and Qpak series pumps utilize an impeller with a single suction
channel where water enters. The impeller develops discharge pressure and directs
the water to a single cutwater* and then to the discharge valves. The impellers are
radially and axially balanced.
Two-Stage
Hale two-stage pumps use two (2) impellers and a transfer valve / switch to develop
the required volume and pressure. (See Figure 2-5: “Two-Stage Pump Overview” on
page 23.)
Note: The transfer valve is a two-position valve that permits the impellers to be operated in
parallel (volume) or series (pressure).
Volume (Parallel) Operation
In Volume operation, the pressure at the pump intake is added to the pressure devel-
oped by both impellers, and the amount of water delivered to the discharge is the sum
of the flows of the two impellers. (See Figure 2-4: “Two-Stage Pump VOLUME Opera-
tion.”)
Figure 2-4: Two-Stage Pump VOLUME Operation
1. The cutwater is a wedge that divides the water between the volute (pump body) and the pump
discharge.