1、A-A-50555 W 9999974 0372775 192 INCH-POUND A-A-50555 December 5,1996 SUPERSEDING 31 January, 1991 MIL-P-21251 COMMERCIAL, ITEM DESCRIPTION PUMPING UNITS, SEWAGE, DUPLEX, CENTRIFUGAL, AUTOMATIC WET-PIT TYPE The General Services Administration has authorized the use of this commercial item description
2、, for all federal agencies. 1. SCOPE. This commercial item description covers automatic, electric-motor-driven, duplex, centrifugal, wet-pit type, sewage pumps. Capacities for each pump of the duplex unit range from 50 to 1,500 gallons per minute (gpm) (3.15 to 94.62 litershec); total dynamic heads
3、range from 10 to 90 feet (3 048 to 27 432 mm). This commercial item description covers pumps intended for use in pumping raw sewage that carries solids fiom a sump tank or tank into a sewer at a higher level. 2. CLASSIFICATION. The unit shall be of two types with capacities as specified herein (see
4、7.2). Type I - Column type Type II - Submerged type 3. SALIENT CHARACTERISTICS. 3.1 Descriution. 3.1.1 Column type. The pumping unit shall consist of two individual, vertical, submerged-type, nonclogging sewage pumps supported fiom motor by extended discharge column and pump shaft. Each pump shall b
5、e furnished with a vertical electric motor, pump-mounting plate, pump support pipe, discharge pipe, lubrication system, and automatic controls and if specified (see 7.2), a sump tank. Options are included in this commercial item description to provide for indoor Beneficial comments, recommendations,
6、 additions, deletions, clarifications, etc. and any data which may improve this document should be sent to: Commanding Officer (Code 1581), Naval Construction Battalion Center, 1000 23rd Avenue, Port Hueneme, CA 93043-4301, AMSC N/A FSC 4630 DISTRIBUTION STATEMENT A. Approved for public release; dis
7、tribution is unlimited. Licensed by Information Handling ServicesProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-50555 9999974 0372976 O29 A-A-505 55 installation of the pumping units and for outside installation where water-tight enclosures for
8、electrical equipment are required. 3.1.2 Submerged type. The pumping unit shall consist of two individual, vertical, submerged-type, nonclogging sewage pumps. Each pump shall be close coupled with a submersible pump motor, discharge pipe, two vertical guide rails, lubrication system, and automatic c
9、ontrols and if specified (see 7.2), a sump tank. Options are included in this commercial item description to provide for indoor installation of the pumping units and for outside installation where water-tight enclosures for electrical equipment are required. 3.2 Standard commercial product. The sewa
10、ge pump shall, as a minimum, be in accordance with the requirements of this commercial item description and shall be the manufacturers standard commercial product. Additional or better features which are not specifically prohibited by this commercial item description but which are a part of the manu
11、facturers standard commercial product, shall be included in the sewage 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 advertisements or manufacturers catalogs, or brochures, and represents
12、the latest production model. 3.3 Design. Pump units and accessories shall be designed to adequately operate and perform to the parameters listed herein. 3.4 Construction. The plan dimensions of the sump cover plate and the length of the pump fi-om the sump cover plate to the bottom of the pump secti
13、on inlet shall be specified (see 7.2) by the requirements of the procuring activity. These requirements may be indicated in the invitation for bids by any one of the following options: a. b. C. Depth and plan dimensions of Government-furnished sump, for which pump is intended, as specified (see 7.2)
14、. The manufacturers standard sump tank is to be furnished with dimensions of pump and tank to be in accordance with manufacturers recommendations for the specified operating characteristics of the pump. If a sump tank is to be furnished, dimensions of the tank are to be as specified (see 7.2), by th
15、e procuring activity. In the event the length of pump is by (a) or (c), the dimensions of the pump from the sump cover plate to the bottom of the suction inlet shall be such as to provide a clearance of not less than one discharge pipe diameter nor more than 18 inches (457 mm) from the floor of the
16、sump or sump tank. 3.4.1 Pump casing. The volute and discharge nozzle of the type I pump casing shall be cast in one piece and shall be designed to permit inspection and removal of the impeller. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-5
17、 055 5 .I 3.4.2 Impeller. Unless otherwise specified (see 7.2), the impeller shall be of the totally enclosed type. 3.4.3 Shaft. Pump shafts for type I units shall be high carbon or alloy steel, unless otherwise specified (see 7.2). 3.4.4 Discharge pipe. A discharge pipe running from the pump discha
18、rge outlet through the sump cover plate shall be funiished as an integral part of the pumping unit. The discharge pipe shall be gastight through the sump cover plate. Unless otherwise specified (see 7.2), the discharge end of the pipe shall terminate in a screwed or flanged connection in accordance
19、with the manufacturers standard practice. 3.4.5 Sump cover plate. If specified (see 7.2), a threaded outlet shall be provided to permit installation of a vent pipe. 3.4.6 Coupling. The coupling shall be of adequate type and size to efficiently transfer load from motor to shaft. 3.4.7 Paint schedule.
20、 Surface preparation and painting shall be as recommended by manufacturer. 3.4.8 Automatic discharge connection (type II only). Each pump shall be hished with a submersible discharge connection system to permit removal and installation of the pump without the necessity of an operator entering the we
21、t well. The design must insure an automatic and firm connection of the pump to the discharge piping when lowered into place. 3.5 Performance. 3.5.1 Capacity. Each pump of the duplex pumping unit shall deliver, at rated speed, not less than the specified (see 7.2) gpm against the specified (see 7.2)
22、dynamic heads, while the liquid level is not more than 1 foot above the datum elevation of the pump. Each pump will handle solids to 3 inches (76 mm), or as specified (see 7.2). Definitions will be to the Hydraulic Institute Standards. 3.6 ComDonents and accessories. 3.6.1 Electric motors. Electric
23、motors for type I shall be of the vertical type and shall be rated and constructed in accordance with the applicable provisions of NEMA MG 1. Motors shall be furnished with drip-proof or NEMA type II, weather-protected enclosures as specified (see 7.2). Voltage, phase, and frequency ratings shall be
24、 as specified (see 7.2). Electrical motors for type II shall conform to NEMA design Class By and incorporate Class F insulation materials to withstand a continuous operating temperature of 31 1 degrees Fahrenheit (“ F) (1 55 degrees Celsius (“ C). The pump and motor shall be capable of handling liqu
25、ids with a maximum temperature of 104“ F (40“ C). The motor shall be protected from thermal and moisture damage. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-50555 9999974 0372978 9T3 m A-A-50555 3.6.2 Electrical controls. Enclosures for con
26、trol switches shall conform to the requirements of NEMA ICs 1 and shall be NEMA type 1, general purpose, NEMA 3R outdoor general purpose, or NEMA type 4 or 4X, water-tight, as specified (see 7.2). 3.6.2.1 Liquid-level control. The pumping unit shall be furnished with the electrical and mechanical de
27、vices required to maintain the level in the sump. The controls shall include an alternating circuit that switches pumps between lead and lag. 3.6.2.2 Water-level alarm. When specified (see 7.2), a water level alarm switch complete with an actuating-mechanism shall be provided for operation on an ele
28、ctrical circuit other than the motor circuit. The switch shall be designed to operate an alarm bell or warning light whenever a predetermined water level (high or low) is reached in the sump because of pump failure, fluid inflow that exceeds the combined capacity of both pumps, or if sump level drop
29、s to a low level that may allow the pump to run dry causing it to burn up. The alarm circuit shall be latching, requiring a reset by an operator. 3.6.3 Sump tank. When specified (see 7.2), a sump tank shall be furnished with the pumping unit. The sump tank shall be constructed using precast concrete
30、, fiberglass, or other specified non-corrosive material (see 7.2). Unless otherwise specified (see 7.2), the dimensions and materials of the tank shall be as recommended by the manufacturer for use with the pumps funiished under this commercial item description. A standard opening for connection to
31、the sewage inflow pipe shall be furnished in the specified size and location with respect to the top of the tank (see 7.2). 4. REGULATORY REQUIREMENTS. 4.1 Materials. The offeror/contractor is encouraged to use recovered materials to the maximum extent practicable, in accordance with paragraph 23.40
32、3 of the Federal Acquisition Regulation (FAR). Unless otherwise specified herein, all equipment, material, and articles incorporated in the work covered by this commercial item description are to be new and fabricated using materials produced from recovered materials to the maximum extent possible w
33、ithout jeopardizing the intended use. The term “recovered materials“ means materials which have been collected or recovered from solid waste and reprocessed to become a source of raw materials, as opposed to virgin raw materials. Unless otherwise specified, none of the above shall be interpreted to
34、mean that the use of used or rebuilt products are allowed under this commercial item description. 4.2 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
35、conversion tables contained in the latest version of Federal Standard No. 376, and all other requirements of this commercial item description including form, fit and function are met. If a product is manufactured to metric dimensions and those dimensions exceed the tolerances specified in the inch-p
36、ound units, a request should be made to the contracting officer to determine if the product is acceptable. The contracting officer has the option of accepting or rejecting the product. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-50555 5. QU
37、ALITY ASSURANCE PROVISIONS. 5.1 Product conformance. The products provided shall meet the salient characteristics of this commercial item description, conform to the producers own drawings, specifications, standards, and quality assurance practices, and be the same product offered for sale in the co
38、mmercial market, The government reserves the right to require proof of such conformance. 6. PACKAGING. Preservation, packing, and markng shall be as specified in the contract or order (see 7.2). 7. NOTES. 7.1 Part Identification Number (PIN). The following part identification numbering procedure is
39、for government purposes and does not constitute a requirement for the contractor. The PIN used for units acquired to this description will be assigned as follows: Total dynamic head Gallons per minute Type: I = Column type II = Submerged type Commercial Item Description number 7.2 Orderinn data. Acq
40、uisition documents should speci the following: a. Title, number, and date of this commercial item description. b. Type of pumping unit (see 2). c. When sump tank is to be furnished (see 3.1.1,3.1.2, and 3.8.3). d. Depth and plan dimensions of sump (see 3.6). e. When impeller is to be other than tota
41、lly enclosed type (see 3.6.2). f. When other materials are required (see 3.6.3). g. When either a flanged or screwed discharge connection is required (see 3.6.4). h. When a threaded outlet is required (see 3.6.5). i. Capacity of each pump of duplex unit in gpm and discharge head in feet of intended
42、installation. Also location point of reference on sump used to determine discharge head (see 3.7.1). j Size of solids to be handled (see 3.7.1). k. Type of motor enclosure (see 3.8.1). 1. Voltage, phase, and frequency ratings (see 3.8.1). m. Type of enclosure for control switches (see 3.8.2). n. Whe
43、n a water-level alarm switch is required (see 3.8.2.2). o. When dimensions and materials of the tank shall be other than the manufacturers standard practice (see 3.8.3). 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-50555 9999974 0372980 55T
44、A-A-50555 p. Location and size of sewage connection when sump tank is furnished (see 3.8.3). q. Level of preservation, packing and marking required (see 6). 7.3 Source of documents. 7.3.1 Copies of specifications and standards required by suppliers in connection with specific procurement functions s
45、hould be obtained Com the procuring activity or as directed by the contracting officer. 7.3.2 NEMA Standards are available Com the National Electrical Manufacturers Association (NEMA), 2101 L Street, N.W., Washington, D.C. 20037. 7.3.3 The Federal Acquisition Regulation (FAR) may be obtained from th
46、e Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. 7.3.4 Hydraulic Institute Standards may be obtained Com the Hydraulic Institute, 712 Lakewood Center North, 14600 Detroit Avenue, Cleveland, Ohio 44 107. 7.4 National Stock Numbers INSNs). The following is a list
47、 of NSNs assigned which correspond to this commercial item description. The list may not be indicative of all possible NSNs associated with the commercial item description. none found 7.5 Capacity. The motor must not overload the entire range of the pump curve. This must be achieved without utilizin
48、g the motors service factor. 7.6 Sump dimensions. Most contractors can furnish standard pumps for sump depths up to 10 feet (3 048 mm). Standard sump tanks are available with diameters Com 30 inches (762 mm) to 48 inches (1 2 19 mm) in 6-inch (1 52 mm) increments. 7.7 Key word listing. Pump, vertica
49、l MILITARY INTEREST: Custodians Navy - YD1 Air Force - 99 Army - AT Review Activities Air Force - 84 Navy - MC, CG DLA - CS Army - CE CIVIL AGENCY COORDINATING ACTIVITY: GSA-FSS Preparing Activity Navy - YD1 (Project 4630-0002) 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
