WKn, WLn-Pumps are multistage centrifugal pumps in ring section design. They are usually mounted on a common base plate with a flexible coupling and driver.

Applications
For waterworks, irrigation and sprinkler installations, as boiler feed or condensate pumps, for high pressure water supply in power systems and presses, as fire pumps, for cooling water systems and hot water circulation.

Construction
The construction is horizontal, multistage, with radially split suction, discharge and stage casings. These casings are sealed by o'rings and held together by external tie bolts. The pump feet are arranged either below the pump or at the centre line according to the number of stages and the temperature.

Balancing Device
The axial hydraulic thrust in WKn pumps is balanced by means of balance holes and throttle gaps at the back shroud of each impeller. Wear rings are supplied at suction and discharge side of each impeller where applicable. The axial thrust in WLn pumps is balanced with a balancing disk arrangement incorporated in a chamber behind the last stage impeller.

Bearings
The bearings are located in two bearing housings, which are positioned at both sides of the pump. WLn pumps can be supplied with plain journal bearings with ring oil lubrication, or alternatively with roller bearings. WKn pumps are fitted with a deep groove ball bearing at the discharge end, which absorbs the residual axial thrust of the rotating assembly. The construction with heavy bearing housing is fitted with angular contact ball bearings at the discharge side in Xarrangement.

Shaft Seal
The shaft is fitted with renewable protecting sleeves in the region of the shaft seal. The uncooled packing stuffing box can be used for operating temperatures up to 105 °C; above this, a cooled packing stufffing box is used, in which a supply of cooling water ensures that the temperature is kept within safe limits. For special applications, special designs of stuffing boxes or mechanical seals can be fitted as required.

Nozzle Orientation
For arrangement "feet below the casing" the suction nozzle is radial, pointing to the right hand side or left hand side or to the top from 2 stages onwards. The discharge nozzle is generally located in the top position. Arrangement "feet in centreline" is only possible for casings of chrome steel or cast steel. In this case nozzle positions are only in top position.

Flanges
Standard construction
DIN 2533/43, PN 16
DIN 2535/45, PN 40
DIN 2546, PN 63
Special constructions of flanges according to USAS and BS and other standards are available on request.