(A) General.
(1) The booster pumps employed within the packaged water booster pumping station shall meet the hydraulic and driver data as set forth in the specification section titled, Operating Conditions. The booster pumps must be installed prior to the station delivery. The installation of the booster pumps shall be as shown on the plans covering this project.
(2) Prior to acceptance of an equipment proposal covering the packaged water booster pumping station, detailed data shall be furnished by the engineer or the owner and shall include the following booster pump information:
(a) Performance curve showing expected performance at points other than the design conditions. Curve shall show head, capacity, efficiency and horsepower based on performance and shall cover the complete operating range of the pump from zero capacity to the maximum capacity. The curve is to also include a net positive suction head required curve; and
(b) Drawings of the proposed equipment giving general dimensions sufficient to determine how the equipment is to be supported and if it will fit within the space available.
(B) Operating conditions. The pump station shall be capable of delivering the fluid medium at the following capacities and heads when operating at zero feet minimum suction pressure. Pumps 1 and 2 shall be designed to deliver adequate domestic flow to all areas of the subdivision or development. Pump 3 shall deliver adequate fire flow to all areas of the subdivision or development. The pump driver shall be of the type as specified for Pumps 1 and 2 and shall be 15 h.p., 1,750 rpm and suitable for three-phase, 60-cycle, 460-volt electrical service.
(C) Horizontal end suction, centrifugal type. The booster pump shall be of the horizontal end suction, centrifugal type. The pumps shall be of close grain cast iron construction complete with bronze trim.
(1) Casing. Volute type, bolted to adapter, with recessed lock fit to ensure alignment. Discharge nozzle can be swivelled to any one of three positions. Separate suction cover bolted to casing through machined lock joint. No stud or bolt holes are tapped through casing to liquid ways. Tapping openings shall be provided for priming, venting, draining and suction and discharge gauge connections. Piping connection to be as shown on plans and as per pump data sheets, NPT threaded nozzles integral with casing or 125 pounds ANSI flat face standard drilled flanges.
(2) Impeller. Enclosed, single suction type, cast in one piece. All impellers are to be statically balanced to ensure smooth operation, also hydraulically balanced, except in some small sizes where end thrust is but a minor factor. Impeller is mounted directly on the extended motor shaft, is keyed to shaft and held in lateral position between shaft sleeve and impeller washer. A self-locking cap nut will hold a compression seal washer securely against hub and prevent leakage or liquid between shaft sleeve and shaft.
(3) Wearing rings. Renewable type; maintain proper running clearance with impeller hubs to minimize leakage between suction and discharge.
(4) Shaft sleeves. To be shouldered on shaft near impeller and covers full length of shaft from impeller hub to motor end bracket. Seals by compression between shaft sleeve and impeller hub, also between sleeve and shoulder on shaft, protecting shaft from contact with liquid. Shaft sleeve is free to expand or contract with temperature changes.
(5) Stuffing box.
(a) The stuffing box shall be cast integral with the pump casing and will be complete with tapped openings for sealed liquid or a flushing connection. The stuffing box shall be suitable for conversion to use standard packing. The stuffing box hardware shall be non-corrosive.
(b) The stuffing box shall contain a face type mechanical seal. The seal shall have a carbon rotating head against a Ni-Resist stationary face and be complete with a Buna-N boot with stainless steel spring and spring retainer.
(6) Adapter. Maintains rigid assembly between motor and casing. Machined lock between adapter and motor end bracket keeps adapter and casing in permanent alignment with motor and extended motor shaft. Sides of adapter are fully open for ready access to stuffing box and gland.
(7) Motor. Assembled as integral part of the complete units. End bracket is machined to match recessed lock fit on adapter to ensure permanent alignment. Shaft carries impeller and sleeve. Motor bearings are ball bearing type, designed to carry all radial and thrust loads and are installed in sealed housings which retain lubricant and exclude dirt and moisture. Motors are drip protected type, having splash proof bracket on outboard end.
(Ord. passed 6-21-2011)