PD model pump units consist of a centrifugal pump and an induction motor, which are mounted on their own fabricated base plates. The pump and motor shafts are connected by means of a rubber-bushed (pin-and-bushing) flexible coupling.
The pump units shall be rigidly anchored to the foundation, and piping shall be rigidly connected to the pumps
The pump as a component of the pump unit is a motor-driven horizontal single-stage axially split volute-casing centrifugal pump with a double entry radial impeller.
The pump casing features semi-spiral inlet hydraulic passages and spiral outlet hydraulic passages. Weld-end suction and discharge nozzles are arranged in the lower casing half and are oriented horizontally in the opposite directions.
The pump casing is near horizontal centerline supported in order to accommodate thermal expansions. In order to allow for free expansion of static components whilst maintaining coupling alignment, the pump feet on the drive side are dowelled to the base plate pedestal with round pins and the other end is provided with a key block at the lower casing part and a keyway in axial direction in the slipper pad (guide piece) on the base plate.
The pump rotor is carried by the plain bearings with ring lubrication. The bearing oil sump is cooled with cooling liquid supplied to a special chamber provided in the bearing housings.
The residual axial thrust of the pump rotor is compensated by an angular-contact thrust ball bearing. This bearing is designed to take up only axial forces and is radially movable.
Pump shaft sealing is by means of stuffing boxes (packed glands) fed with cooling and sealing liquid from an external source.
Coverage chart of the PD Model Pumps:
Performance of the PD Series Pumps:
|Pump make|| |
|Capacity, m3/h||Head, m||Speed of rotation, rpm||Power input (r=907 kg/m3), kW||Efficiency, %||NPSH required, m|
|PD 650-160 UKhL4 |
PD 650-160 Т3