The pump(s) shall be of the vertical submerged axial flow propeller/mixed flow type, Cascade Model . . . or approved equal. The pump is to be suspended from a mounting baseplate at elevation . . . The pumping element shall be suspended on a sufficient length of column to permit dewatering the sump to elevation . . . The center-line of the horizontal discharge shall be above/below the mounting baseplate at elevation . . . The discharge connection shall be plainend suitable for a flexible pipe coupling/flanged with an ASA rating of . . . /grooved for a rigid type pipe coupling. The suction inlet shall be flared to resist the formation of damaging vortices. The complete unit when operating within the specified head range shall be free of excessive vibration, cavitation and noise. The design of component parts hall be interchangeable with parts of like equipment. The column sections shall be flanged on each end with a register machined on centers to assure positive alignment when connected to mating parts. The pump driver shall incorporate a thrust bearing capable of withstanding the hydraulic thrust produced by the pump when operating at any condition in the specified head range of the pump. Design shall be such that no damage will occur in the event of reverse rotation caused by backflow of water through the pump.

SAMPLE SPECIFICATION

Design Data

General
The pump(s) shall be of the vertical submerged axial flow propeller/mixed flow type, Cascade Model . . . or approved equal. The pump is to be suspended from a mounting baseplate at elevation . . . The pumping element shall be suspended on a sufficient length of column to permit dewatering the sump to elevation . . . The center-line of the horizontal discharge shall be above/below the mounting baseplate at elevation . . . The discharge connection shall be plainend suitable for a flexible pipe coupling/flanged with an ASA rating of . . . /grooved for a rigid type pipe coupling. The suction inlet shall be flared to resist the formation of damaging vortices. The complete unit when operating within the specified head range shall be free of excessive vibration, cavitation and noise. The design of component parts hall be interchangeable with parts of like equipment. The column sections shall be flanged on each end with a register machined on centers to assure positive alignment when connected to mating parts. The pump driver shall incorporate a thrust bearing capable of withstanding the hydraulic thrust produced by the pump when operating at any condition in the specified head range of the pump. Design shall be such that no damage will occur in the event of reverse rotation caused by backflow of water through the pump.

Performance Requirements
The pump shall be designed to give . . . GPM while operating against a total head of . . . feet as measured at the pump discharge. The total head includes the vertical difference in feet between the normal operating water level in the sump and highest water elevation in the system, all internal friction losses in the piping system and the velocity head for the design capacity. It shall be the pump manufacturer’s responsibility to compute and add the internal pump losses to the total head to determine the total dynamic bowl head of the pump. In addition to the rated head and capacity, the pump must be capable of pumping . . . FPM at a total head of . . . feet. The minimum bowl efficiency at the rated total dynamic bowl head shall be . . . %. The discharge pipe shall be sized such that the velocity of the water being pumped, at the maximum capacity condition will not exceed 12 feet per second.

The suction and discharge bowl shall be of cast iron with a minimum tensile strength of 30,000 p.s.i. The impeller/propeller shall be cast bronze and locked to the bowl shaft by a key and thrust collar. The bowl shaft shall be made from type 416 stainless steel and polished at each bearing journal.

The size of the shaft shall be sufficient to safely transmit the required brake horsepower to the impeller to produce the specified performance. Bronze bushings shall be provided immediately above and below the impeller/propeller.

The elbow and column shall be of fabricated mild steel with a minimum thickness of ¼”. The elbow shall be 45º insert/long radius/right angle varied type. The lower section may be tapered for connection to the discharge bowl.

The lineshaft shall be made from carbon steel and supported by bearings. The lineshaft bearings shall be threaded externally to act as a coupling for extra heavy steel enclosing tubes. The lineshaft bearings shall be bronze of the removable type and must be provided with a means of passing oil from one bearing to the next. A means shall be provided for tension loading of the enclosing tube.

The lineshaft bearings shall be lubricated by a drip-feed oil system utilizing an oil reservoir solenoid valve with a voltage of . . . and needle valve dripper. The suction bowl bushing shall be grease packed.