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1、American Water Works Association ANSIIAWWA C510-97 (Revision of ANSVAWWA (2510-92) AWWA STANDARD FOR DOUBLE CHECK VALVE BACKFLOW PREVENTION ASSEMBLY Effective date: Feb. 1, 1998. First edition (AWWA C506) approved by AWWA Board of Directors Jan. 27, 1969. This edition approved June 15, 1997. Approve
2、d by American National Standards Institute Dec. 2, 1997. AMERICAN WATER WORKS ASSOCIATION 6666 West Quincy Avenue, Denver, Colorado 80235 STD-AWWA C510-ENGL 1777 = 0783350 0505777 707 A W A Standard This document is an American Water Works Association (AWWA) standard. It is not a specification. AWWA
3、 standards describe minimum requirements and do not contain all of the engineering and administrative information normally contained in specifications. The AWWA standards usually contain options that must be evaluated by the user of the standard. Until each optional feature is specified by the user,
4、 the product or service is not fully defined. AWWA publication of a standard does not constitute endorsement of any product or product type, nor does AWWA test, certie, or approve any product. The use of AWWA standards is entirely voluntary. AWWA standards are intended to represent a consensus of th
5、e water supply industry that the product described will provide satisfactory service. When AWWA revises or withdraws this standard, an oficial notice of action will be placed on the first page of the classified advertising section of Journal AWWA. The action becomes effective on the first day of the
6、 month following the month of Journal AWWA publication of the official notice. American National Standard An American National Standard implies a consensus of those substantially concerned with its scope and provisions. An American National Standard is intended as a guide to aid the manufacturer, th
7、e consumer, and the general public. The existence of an American National Standard does not in any respect preclude anyone, whether that person has approved the standard or not, from manufactur- ing, marketing, purchasing, or using products, processes, or procedures not conforming to the standard. A
8、merican National Standards are subject to periodic review, and users are cautioned to obtain the latest editions. Producers of goods made in conformity with an American National Standard are encouraged to state on their own responsibility in advertising and promotional materials or on tags or labels
9、 that the goods are produced in conformity with particular American National Standards. CAUTION NOTICE: The American National Standards Institute (ANSI) approval date on the front cover of this standard indicates completion of the ANSI approval process. This American National Standard may be revised
10、 or withdrawn at any time. ANSI procedures require that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of publication. Purchasers of American National Standards may receive current information on all standards by calling or writing the American
11、National Standards Institute, 11 W . 42nd St., New York, NY 10036; (212) 642-4900. Copyright O 1998 by American Water Works Association Printed in USA 11 -,-,- STD-AWWA CSLU-ENGL 1777 0783350 0505778 843 Committee Personnel The AWWA Standards Committee on Backflow Preventers, which reviewed and appr
12、oved this standard, had the following personnel at the time of approval: James T. Cowgill, Chair Richard A. Coates, Secretary Consumer Members P.J. Brady, Department of Public Utilities, County of Henrico, S.A. Brook, Orange County Public Utilities, Orlando, Fla. E.J. Havlina, Los Angeles Department
13、 of Water and Power, O.J. Jones, Cincinnati, Ohio C.L. Nena, California Water Service Company, Montebello, Calif P.W. Orvin, City of Jacksonville, Jacksonville, Fla. Richmond, Va. Los Angeles, Calif. General Interest Members G.J. Angele Sr., Oak Ridge, Tenn. S.F. Asay, Stuart F. Asay that moving par
14、ts do not bind or gall; and that there be no distortion that will interfere with the intended performance of the assembly. Flow channels shall be streamlined to prevent cavitation, minimize pressure loss, and eliminate pockets that could entrap foreign materials. 4.3.1.1 Access to internal parts. Al
15、l internal parts shall be accessible for inspection, repair, and renewal without removing the assembly from the line using the shutoff valves to isolate the backflow preventer. STD-AWWA CSlO-ENGL L977 U 0783350 0505787 b27 W 6 AWAC510-97 4.3.1.2 Area of waterways. The assembly shall be designed so t
16、hat the minimum waterway area normal to the direction of flow shall not adversely affect the overall pressure loss. 4.3.1.3 Clearance of moving parts. Clearance between valve stems and asso- ciated guides, hinge pins and bushings, and other similar parts shall be designed to yield a low probability
17、of malfunctioning due to corrosion or deposit of foreign matter on surfaces of the assembly. Minimum clearance between the body of the check valve and hinge arm, clapper, counterweight, poppet valve, or other free-moving part shall be as follows: 1. Iron-body parts of all sizes: ?h in. (12 mm). 2. B
18、rass or bronze parts up to and including l-in. (25-mm) size: Va in. (3 mm). 3. Brass or bronze parts greater than l-in. (25-mm) size: Y 4 in. (6 mm). 4.3.1.4 Facing rings for poppet-type valves. For all sizes of poppet valves, the elastomer disc shall be supported by an adequate bearing surface, suc
19、h that the elastomer disc will comply with all tests contained in this document. The facing ring shall overhang the outside edge of the seat ring by at least Yi6 in. (1.6 mm). There shall be a minimum of 1/16 in. (1.6 mm) between the inside edge of the seat ring and the facing ring clamp. The elasto
20、mer disc shall be sup- ported by an adequate bearing surface, such that the elastomer disc will comply with all tests contained in this document. In sizes up to 2 in. (50 mm), the facing ring shall overhang the outer edge of the sealing surface of the seat ring by at least 1/8 in. (3 mm). In sizes o
21、f 2 in. (50 mm) and larger, the overhang shall be at least Y 4 in. (6 mm). There shall be a minimum of Yi6 in. (1.6 mm) between the inside edge of the seat ring and the facing ring clamp. 4.3.1.6 Bushings. All bushings shall project at least Y 4 in. (6 mm) inside the body of the component involved.
22、4.3.1.7 Connections. End connections, test cocks, and control piping connec- tions to components of the backflow prevention assembly shall be either threaded in accordance with ANSYASME B1.20.1, or flanged in accordance with ANSUASME B16.1, ANSUASME B16.24, or ANSVAWWA CllO/A21.10, or grooved and sh
23、ouldered joints per ANSYAWWA C606. 4.3.1.8 Test cocks. Resilient-seated full-ported test cocks shall be attached to corrosion-resistant nipples or shall have male threads to be installed in tapped holes. At each location on a valve body where such a tapped hole is required, there shall be a boss to
24、permit sufficient threading for nipples. Test cocks shall have female iron pipe size (IPS) ends on the discharge side, Test connections of in. (3 mm) shall be permitted to be either IPS female threads or male Y4 in. (6 mm) flared-type connections per SAE 5513. The minimum sizes (IPS) of test cocks s
25、hall be YB in. (3 mm) for assemblies up to and including l-in. (25-mm) nominal size; Y4 in. (6 mm) for assemblies up to and including 2-in. (50-mm) nominal size; ! h in. (12 mm) for assemblies 2%-in. through 4-in. (63-mm through 100-mm) nominal size; and 9 4 in. (19 mm) for assemblies 6 in. (150 mm)
26、 and larger. Test cocks shall be installed at the following locations on all backfiow prevention. assemblies: 4.3.1.5 Facing rings for swing-type valves. 1. On the supply (inlet) side of the supply shutoff valve. 2. Between the supply shutoff valve and the first check valve. 3. Between the check val
27、ves. 4. Between the second check valve and the shutoff valve on the outlet side of the assembly. -,-,- STD.AWWA CSLO-ENGL 1997 0783350 0505790 340 E DOUBLE CHECK VALVE ASSEMBLY 7 4.3.1.9 Valve seats. Provision shall be made for renewal and replacement of valve seats in iron-body components. 4.3.1.10
28、 Alignment of check valves. Each clapper disk, facing ring, and clamping and securing bolt or stud shall be concentric to an axis that is normal to the face of the facing ring. When applicable, the unit shall be designed so that the facing ring may be clamped and reclamped without warping its face.
29、The clapper must not be able to tip and catch under the seat ring. When clappers or poppets are in a wide-open position, they must bear on a definite stop that is so designed and placed that the action of the water will not twist or bend the valve parts or cause them to chatter. The design shall be
30、such that at all flow rates, from zero to (and including) rated flow, the component parts shall not create any chatter or noise. All working parts shall be designed and supported in a manner to preclude distortion or misalignment. 4.3.1.11 Shutoff valves. Resilient-seated shutoff valves shall be con
31、sidered an integral part of the assembly. For the 3-in. (75-mm) and larger assemblies, the resilient-seated gate valves shall conform to ANSIAWWA (2509. The 2Ih-in. (64-mm) gate valves are to be constructed according to the applicable requirements of ANSI/ AWWA C509 even though they are not specific
32、ally listed in the standard. Shutoff valves smaller than 2%-in. (64-mm) size shall be resilient seated and of a quality acceptable to the purchaser. Ferrous metal surfaces shall be coated with a polymerized coating in accordance with ANSIAWWA C550. 4.3.1.12 Provision shall be made for bleeding trapp
33、ed air from components of the assembly. 4.3.2 Operating requirements for double check valve backflow prevention assembly. 4.3.2.1 General. The check valves shall be loaded internally so that when the supply pressure is at least 1 psi (6.89 kPa) and the outlet pressure is atmospheric, each check valv
34、e will be driptight in the normal direction of flow. There shall be no leakage past any check valve when the pressure conditions that cause backflow are present. All components of the assembly shall operate at, and withstand a thermal test at, the greater of 140F (60C) or at the maximum working wate
35、r temperature (MWWT), maximum working water pressure (MWWP), and the flow rate as specified in Table 2, for a minimum period of 100 hours without any leakage, damage, permanent deformation, or impairment of operation. During and after a minimum of 100 hours at rated temperature and pressure the asse
36、mbly shall operate satisfactorily per Sec. 4.3.2.1. 4.3.2.2 Operation at rated temperature and pressure. Table 2 Thermal test minimum flow rates Size of Assembly in. mm) Minimum Flow Rate m m (L Is) ?A (6) 3 h (9) 92 (12) 94-1 (19-25) 1 1/4-2 (3 1-50) 21/2-12 (64-3 05) 1 (0.06) 3 (0.19) 7.5 (0.47) 3
37、0 (1.89) 40 (2.52) 50 (3.15) -,-,- STD-AWWA C5LO-ENGL 1997 0783350 0505771 287 a AWWA c510-97 4.3.3 InstuZZution instructions. The manufacturer shall include with each unit installation instructions attached to the unit. Sec. 4.4 Workmanship 4.4.1 Foundry und machine work. All foundry and machining
38、work shall be performed in accordance with the best modern practice for the class of work involved. All parts shall conform, within allowable tolerances, to the manufacturers specifica- tions and shall be free from defects. 4.4.2 Joints. Ail flanged joints shall be faced true and machined at right a
39、ngles to their respective axes; threaded joints must be concentric and accurately cut. 4.4.3 Bronze mounting. All ferrous parts receiving a bronze mounting shall be finished to fit. Such handwork as is required in finishing shall produce a neat, professional, well-fitting, and smoothly operating pro
40、duct. All castings shall be clean and sound without defects that will weaken their structure or impair their service. Plugging, welding, or repairing of cosmetic defects is allowed. Repairing of structural defects is not allowed unless agreed to by the purchaser. Repaired valves shall comply with th
41、e testing requirements of this standard after repairs have been made. Repairs within the bolt circle of any flange face are not allowed. 4.4.4 Castings. SECTION 5: VERIFICATION Sec. 5.1 Testing and Uniformity All joints shall be watertight when subjected to water pressure at twice the maximum workin
42、g water pressure. All assembly parts of the same size, model, and manufacture shall be interchangeable. SECTION 6: DELIVERY* Sec. 6.1 Marking Backflow prevention assemblies shaI1 be marked distinctly with the size, model designation, and serial number. The markings, which shall not be easily defaced
43、, shall be either cast or stamped in the metal or stamped on a brass or stainless-steel nameplate permanently affixed to the assembly. Serial numbers, size, and model shall be at least 3/1s in. (5 mm) in height. The markings shall include the following: 1. Name of manufacturer or trademark. 2. Type:
44、 double check valve or DC. 3. Size. 4. Model designation. 5. Direction of flow (indicated by an arrow). *Governmental marking, packaging, and shipping references reflect US requirements. Users of AWWA C510 in Canada, Mexico, and non-North American countries should verify applicable local and nationa
45、l regulatory requirements. -,-,- STD-AWWA CCILO-ENGL 1977 0783350 0505772 113 I I DOUBLE CHECK VALVE ASSEMBLY 9 6. Serial number. 7. 8. Maximum working water pressure (MWWP). Maximum working water temperature (MWWT) (in degrees Fahrenheit or Celsius). Sec. 6.2 Preparation for Shipment Backflow preve
46、ntion assemblies shall be complete when shipped. The manufac- turer shall use due and customary care in preparing the assemblies for shipment so that no damage as a result of the manufacturers negligence occurs in handling or in transit. The backfiow prevention assemblies shall be drained completely
47、 and all openings closed completely before shipment. Sec. 6.3 Affidavit of Compliance If required by the purchasers specifications, the supplier shall furnish an affidavit certifying that the assemblies furnished comply with all applicable requirements of this standard. If required by the purchasers
48、 specifications, the supplier shall furnish a certificate of approval from a laboratory recognized as having expertise in this specialized field. 6.3.1 Requirements for approval. Each backflow prevention assembly approved by the testing laboratory shall satisfactorily pass a laboratory evaluation an
49、d field evaluation in accordance with the requirements of this section. 6.3.1.1 Evaluation in the laboratory. One or more units, selected at random by the testing laboratory from the manufacturers stock, shall be thoroughly evaluated by the testing laboratory as to the units design and operating characteris- tics up to the assemblies rated temperature and pressure. This evaluation shall include a