Pump Type Follows:

Wednesday, April 8, 2009

Vertical Single Suction Pump

Vertical single suction pumps with bottom suction are commonly used for larger sewage, water supply or condenser circulating applications. Such pumps are provided with wing feet that are bolted to soleplates grouted in concrete pedestal or piers. Sometimes the wing feet may be grouted right in the pedestal. This must be suitably arranged to provide proper access to any handholes in the pump and to allow clearance for the elbow suction nozzle if these are used.

If a vertical pump is applied to a condensate service or some other service for which the eye of the impeller must be vented to prevent vapor binding, a pump with a bottom single inlet impeller is not desirable because it does not permit effective venting. Neither does vertical pump employing a double suction impeller. The most suitable design for such applications incorporate a top single inlet impeller.

If the driver of a vertical pump can be located immediately above the pump, it is often supported on the pump itself. The shaft of the pump and driver may be connected by flexible coupling, which required that each have its own thrust bearing. If the pump shaft is rigidly coupled to the driver shaft or an extension of the driver shaft, a common thrust bearing is used, normally in the driver.

Although the driving motors are frequently mounted on top of the pump casing, one important reason for the use of the vertical shaft design is the possibility of locating the motors at an elevation sufficiently above the pump to prevent the accidental flooding of the motors. The pump and its driver may be separated by an appreciable length of shafting, which may required already bearing between the two units.

Bearings for vertical dry-pit pumps and for intermediate guide bearings are usually antifriction grease lubricated types to simply the problem of retaining a lubricant in a housing with a shaft projecting vertically through it. Larger units, for which antifriction bearing are not available or desirable, use self-oiling Babbitt steady bearings with spiral oil grooves. The pump is connected by rigid coupling to its motor which is provided with a line and a thrust bearing.