A-A-50560 Pumps, Centrifugal, Water Circulating, Electric-Motor-Driven No S/S DocumentThis Commercial Item Description CID covers electric-motor-driven, centrifugal, water circulating pumps for use in hot water heating systems and service water distribution systems. The pumps have in-line connections to permit unsupported installation of the units in a straight run of piping. Pumps covered by this document are intended for use as circulators in forced hot water heating systems, and in service water distribution systems, where the water temperature for either application does not exceed 225 Degrees F 107 degrees C.

Pages 1 - 2 - 3 - 4 - 5

A-A-50560

3. SALIENT CHARACTERISTICS.

3.1 Description. The pumps covered by this CID shall be the in-line centrifugal, electric motor-driven type. The motor shall be supported in a mounting bracket attached to the pump casing to form an integrated, self-contained unit. The size of the pump is determined by the diameter, in inches (mm), of the discharge.

3.2 Standard commercial product. The pumps shall, as a minimum, be in accordance with the requirements of this CID and shall be the manufacturer's standard commercial product.

Additional or better features which are not specifically prohibited by this CID but which are a part of the manufacturer's standard commercial product, shall be included in the pumps being furnished. A standard commercial product is a product which has been sold or is being currently offered for sale on the commercial market through advertisement or manufacturer's catalogs or brochures, and represents the latest production model.

3.3 Performance. The pump shall be capable of meeting the capacity and total dynamic head requirements specified (see 7.3), based on pumping water at a temperature of 80 degrees Fahrenheit ( F) (27 degrees Celsius ( C)). Pumps shall be capable of continuously delivering its rated capacity at a pump efficiency of not less than 50 percent, or where applicable, NEMA MG1 efficiencies shall apply. The pumps shall be capable of handling water at temperatures up to

225 F (107 C). The pump shall be capable of withstanding a hydrostatic pressure of not less than

1.5 times the maximum rated head of the pump.

3.4 Construction. The pumps shall include a motor, motor mounting bracket, and pump with inlet and outlet connections on opposite sides of the casing on a common centerline. Pumps shall be constructed to permit unsupported installation in a straight run of horizontal or vertical piping. The pump casing, impeller, and shaft shall be in accordance with standard industry practice for the service required.

3.4.1 Connections. Inlet and outlet connections shall be flanged and furnished with threaded companion flanges.

3.4.2 Motor. The motor shall be constructed and rated in accordance with the applicable provisions of NEMA MG 1 and shall prevent overloading at any point on the pump performance curve in accordance with NFPA 70. The size, type, and style of motor shall be in accordance with standard industry practice.

3.5 Metric products. Products manufactured to metric dimensions will be considered on an equal basis with those manufactured using inch-pound units, provided they fall within specified tolerances using conversion tables contained in the latest version of FED-STD-376, and all other requirements of this CID are met. If a product is manufactured to metric dimensions and those dimensions exceed the tolerances specified in the inch-pound units, a request should be made to the specification preparing activity for changes to this document.