1、ASSE Standard #1024 - 2004ASSE Board Approved: February 2004Performance Requirements for Dual Check Backflow PreventersASSE InternationalDual Check Backflow Preventers iASSE #1024 - 2004General InformationNeither this standard, nor any portion thereof, may be reproduced without the written consent o
2、f ASSE International.No product may be said to be ASSE approved unless the manufacturer has applied to the ASSE has had his product tested according to the applicable ASSE Standards, and when the product has passed the test, displays the ASSE Seal on the product.Instructions for receiving the author
3、ization to display the Seal are available from ASSEs International Office. Organizations wishing to adopt or list any ASSE Standard should print the ASSE Standard number on the cover page first and in equal or larger type to that of the adopting or listing organization.ASSE InternationalMokena, Illi
4、noisCopyright 2004, 1994, 1988, 1979All rights reserved.ii Dual Check Backflow PreventersASSE #1024 - 2004Dual Check Backflow Preventers iiiASSE #1024 - 2004ForewordThis foreword shall not be considered a part of the standard, however, it is offered to provide background information.ASSE Internation
5、al is dedicated to the preservation of public health and safety through “Prevention Rather than Cure.”Prevention of contamination or pollution of potable water in plumbing systems is one of the major objectives of the Societys Standards Program, which is addressed to the development and promulgation
6、 of Standards embracing performance criteria for manufactured plumbing components designed to safeguard public health and safety.The recognition of probable sources or causes of contamination or pollution of a potable water system whereby it becomes unfit or undesirable for human consumption, is vit
7、al to the maintenance of its continued potability.There are two basic and practiced methods for the protection of potable water supplies:(a) Protection by containment is the isolation, by a suitable means, of the system within the premises supplied, which could be a source of contamination or pollut
8、ion, from the vendors or public water supply system.(b) Protection of each individual outlet within the premises which could be a source of contamination or pollution, by a suitable device or means.Protection by containment protects the vendors or public water supply only. It does not provide protec
9、tion within the premises supplied.In modern plumbing systems, there are many situations where backflow could occur due to back pressure conditions. In some cases the backflow of pollutants into the potable water system could cause serious health hazards, while in other cases the backflow of pollutan
10、ts into the potable water system would make it undesirable, yet not a health hazard, to the persons consuming it (low hazard).This standard focuses on those devices know as Dual Check Valves, which will fulfill “Low Hazard” protective needs.The devices described are suitable for either protection by
11、 containment at residential supply service lines, or protection of individual outlets where pollutants, which could be caused to enter the potable water, are of low hazard.iv Dual Check Backflow PreventersASSE #1024 - 2004These devices are generally suitable for cold water service under continuous o
12、r intermittent pressure conditions. Usage with hot water is limited to the temperature specified by the manufacturer, and when certified under this standard.This standard was first adopted in 1979, and was the latest addition to the ASSE Backflow Preventer Standards, each of which covers a different
13、 type of backflow protection device, each tailored to the protective requirements essential to the specific system conditions in which it is installed and the degree of hazard involved.Although many of the material specifications are detailed within Section 4.1 of this standard, it is the responsibi
14、lity of the manufacturer to comply with the requirements of the Safe Drinking Water Act, United States Public Law 93-523.This standard was promulgated in accordance with procedures developed by the American National Standards Institute (ANSI).Compliance with this standard does not imply acceptance b
15、y any code group unless the standard has been adopted by the code.Dual Check Backflow Preventers vASSE #1024 - 2004Richard J. ProspalProduct Standards Committee ChairmanProspal Consulting Services, Inc.Brunswick, OhioRand H. AckroydRand EngineeringNewburyport, MassachusettsMichael BeckwithState of W
16、isconsin Department of CommerceMadison, WisconsinGunnar O. CollinsCollins Backflow Specialists, Inc.Palatine, IllinoisJud CollinsOklahoma State Health DepartmentOklahoma City, OklahomaShannon M. Corcoran ASSE Standards CoordinatorWestlake, OhioA. Richard EmmersonGeneral InterestBuffalo Grove, Illino
17、isSteven HazzardASSE Staff EngineerWestlake, OhioDale HollowaySGS United States Testing CompanyTulsa, Oklahoma2003-04 Product Standards CommitteeMichael KobelInternational Association of Plumbing and Mechanical OfficialsWalnut, CaliforniaValentine Lehr, P.E.Lehr AssociatesNew York, New YorkPeter Mar
18、zecUnited Association of Plumbers and PipefittersWashington, D.C.Perry W. Meikle, Jr.Perry W. Meikle Consulting EngineerAntioch, CaliforniaShabbir RawalpindiwalaKohler CompanyKohler, WisconsinLynne Simnick International Code Council, Inc.Country Club Hills, IllinoisJack VilendrePrecision Plumbing Pr
19、oducts, Inc.Portland, OregonDavid ViolaPlumbing Manufacturers InstituteSchaumberg, IllinoisJoseph C. Zaffuto, P.E.ASSE Staff EngineerWestlake, Ohiovi Dual Check Backflow PreventersASSE #1024 - 2004Rand H. AckroydRand EngineeringNewburyport, MassachusettsRobert Castle, PEHoneywell Water ControlsWarwi
20、ck, Rhode IslandBill DunmireFEBCO, Division of SPX Valves and ControlsSt. Pauls, North CarolinaScott FarnhamFord Meter Box Co.Wabash, IndianaSteven HazzardASSE Staff EngineerWestlake, OhioJohn HigdonConbraco Industries, Inc.Matthews, North Carolina1024 Working GroupBob Martin, Jr.Wolverine Brass Wor
21、ksConway, South CarolinaTeresa MedranoWilkins, Division of ZurnPaso Robles, CaliforniaBrad NollWilkins, Division of Zurn IndustriesPaso Robles, CaliforniaGeorge SwensonFlomatic Valves - Flomatic Corp.Glens Falls, New YorkJoseph C. Zaffuto, P.E.ASSE Staff EngineerWestlake, OhioDual Check Backflow Pre
22、venters viiASSE #1024 - 2004Table of ContentsSection I . 11.0 General . 11.1 Application 11.2 Scope . 11.3 Reference Standards . 1Section II 22.0 Test Specimens 22.1 Samples Submitted for Test . 22.2 Drawings 22.3 Rejection 2Section III . 33.0 Performance Requirements and Compliance Testing 33.1 Con
23、nection Torque . 3Table 1 33.2 Hydrostatic Test of Complete Device . 3Figure 1 43.3 Hydrostatic Leakage Tests of Check Valves 4Figure 2 53.4 Flow and Pressure Loss . 5Table 2 63.5 Drip Tightness of Check Valves 63.6 Deterioration at Maximum Rated Temperature and Pressure 7Figure 3 8Table 3 83.7 Chec
24、k Valve Operation . 93.8 Dual Check Valve Integrity at Maximum Intermittent Rated . 9Table 4 9Section IV 104.0 Detailed Requirements . 104.1 Materials . 104.2 Repairability . 114.3 Instructions for Marking and Installation 11Section V . 125.0 Definitions . 12viii Dual Check Backflow PreventersASSE #
25、1024 - 2004Dual Check Backflow Preventers 1ASSE #1024 - 2004Dual Check Backflow PreventersSection I1.0 General1.1 ApplicationThis standard applies to devices classified as dual check backflow preventers (herein referred to as “device”). The purpose of this device is to keep polluted water from flowi
26、ng back into the potable water system, when pressure is temporarily higher in the polluted part of the system than in the potable water piping. The devices covered by this standard are intended to protect the potable water supply from low hazard pollution at residential service lines and individual
27、outlets. These devices are intended for cold water service under continuous or intermittent pressure conditions. Usage with hot water is limited to the temperature specified by the manufacturer.1.2 Scope1.2.1 DescriptionThis device consists of two (2) independently acting check valves, internally fo
28、rce loaded to a normally closed position, designed and constructed to operate under intermittent or continuous pressure conditions.1.2.2 Size RangeThe device shall be designed to accommodate the following nominal pipe sizes: 1/4 NPS, 3/8 NPS, 1/2 NPS(5/8 water meter), 3/4 NPS, 1 NPS, 1-1/2 NPS and 2
29、 NPS ( 8 DN, 10 DN, 15 DN, 20 DN, 25 DN, 40 DN and 50 DN).Note: Devices with a 5/8 water meter connection shall meet the flow requirements of a 1/2 inch (15 DN) nominal pipe size.1.2.3 Pressure RangeThe device shall be designed for a working pressure of up to a minimum of 160.0 psi ( 1103.2 kPa).1.2
30、.4 Temperature Range(a) Cold water service ranges from 40.0 F to 110.0 F (4.4 C to 43.3 C), or the manufacturers maximum rated temperature, whichever is greater.(b) Hot water service ranges from 40.0 F to 180.0 F (4.4 C to 82.2 C), or the manufacturers maximum rated temperature, whichever is greater
31、.1.2.5 Flow CapacityThe device shall meet the minimum water flow capacities at or below the maximum pressure loss specified in Section 3.4.1.3 Reference StandardsReference to industry standards shall mean the latest edition of the standard.2 Dual Check Backflow PreventersASSE #1024 - 2004Section II2
32、.0 Test Specimens2.1 Samples Submitted for TestThree (3) devices of each model and size shall be submitted by the manufacturer. Tests shall be performed in the order listed on one (1) device.2.2 Samples TestedThe testing agency shall select one (1) of each model and size for full test.2.3 DrawingsAs
33、sembly and installation drawings and other data which are needed to enable a testing agency to determine compliance with this standard shall accompany devices submitted for examination and performance testing under this standard.2.4 RejectionFailure of one (1) device shall result in a rejection of t
34、hat model and size until the manufacturer has corrected the fault and submitted new devices for testing.Dual Check Backflow Preventers 3ASSE #1024 - 2004Section III3.0 Performance Requirements and Compliance Testing3.1 Connection Torque3.1.1 PurposeThe device shall be capable of withstanding, withou
35、t deformation, breakage or leakage, the following torque exerted at the end connection of the device to the pipe line.3.1.2 ProcedureInstall the device in its normal operating position. With the inlet securely anchored, apply the torque shown in Table 1 for a period of not less than five (5) minutes
36、. The device shall be pres-surized at 160.0 psi (1103.2 kPa) or the manufacturers maximum rated working pressure, whichever is greater, during the torque test.Table 1Nominal Pipe Size Turning EffortNPS1/43/81/25/83/411-2DN810151820254050 N m17.022.633.933.950.950.981.4108.5pound-inches150.0200.0300.
37、0300.0450.0450.0720.0960.03.1.3 CriteriaAny indication of damage that prevents full compliance with any part of this standard shall result in the rejection of the device.3.2 Hydrostatic Test of Complete Device3.2.1 PurposeThe purpose of this test is demonstrate the devices ability to withstand a pre
38、ssure of 320.0 psi (2206.5 kPa) or two (2) times the manufacturers maximum rated working pressure, whichever is greater.3.2.3 ProcedureInstall the device as shown in Figure 1. Purge the system of air and pressurize it to the test pressure. Maintain the pressure for ten (10) minutes. Observe for exte
39、rnal leaks or other indications of damage.4 Dual Check Backflow PreventersASSE #1024 - 2004Figure 1Flow MeterUpstream Tee (See Figure 2)Check Valve #2Check Valve #1GaugeRing PiezometerMinimum five (5) diameters of straight pipe.Approximately ten (10) diam-eters of straight pipe.Throttling ValveSuppl
40、y ValveGaugeShut-off ValveShut-off ValveRing PiezometerDual Check3.2.3 CriteriaAny leaks shall result in the rejection of the device. Any damage that prevents compliance with any part of this standard shall also result in the rejection of the device.3.3 Hydrostatic Leakage Tests of Check Valves3.3.1
41、 PurposeThe purpose of this test is to determine whether leaks or damage occurs when the device is subjected to 320.0 psi (2206.5 kPa), or two (2) times the manufacturers maximum rated working pressure, whichever is greater applied to the downstream side of each check valve individually.3.3.2 Proced
42、ure3.3.2.1 Upstream Check ValveInstall the device as shown in Figure 1, with a sight glass (See Figure 2), shut-off and drain cock installed in the tee upstream of the inlet check valve. Hold the downstream check valve partially open (fully clear of its seat). Purge the device of air, close the supp
43、ly valve, open the shut-off cock to the sight glass. Adjust the water level in the sight glass to be at the height not less than that corresponding to the top of the water space in the device. Raise the pressure on the downstream side of the check valve to 320.0 psi (2206.5 kPa) or two (2) times the
44、 manufacturers maximum rated working pressure of the device, whichever is greater, and record the water level in the sight glass. Hold for five (5) minutes. Observe for indications of damage or leakage by the check valve. Water rise due to disc compression shall not be cause for rejection of the dev
45、ice.Dual Check Backflow Preventers 5ASSE #1024 - 2004Figure 23.3.2.2 Downstream Check ValveRepeat the test with the upstream check valve held partially open (fully clear of its seat), the sight glass installed as described in Section 3.3.2.1, the downstream check in a fully closed position and a pre
46、ssure of 320.0 psi (2206.5 kPa) or two (2) times the manufacturers maximum rated working pressure, whichever is greater, applied on the downstream side of the check valve with atmospheric pressure on the upstream side. Hold for five (5) minutes and observe for indication of damage or leakage by the
47、check valve. Water rise due to disc compression shall not be cause for rejection of the device.3.3.3 CriteriaAny leaks or a rise in the water level in the sight glass (other than that due to disc compression) shall result in the rejection of the device. Any damage that prevents compliance with any p
48、art of the standard shall result in the rejection of the device.3.4 Flow and Pressure Loss3.4.1 PurposeThe purpose of this test is to determine whether the device meets the minimum water flow requirement at or below the maximum allowable pressure loss across the device of 10.0 psi (69.0 kPa).3.4.2 P
49、rocedureInstall the device as shown in Figure 1, with a differential manometer or pressure indicating instrument connected to positions where the gauges are shown. These connections shall be to ring piezometers. The supply source shall be capable of supplying a volume of water adequate to meet the flow requirements of the device being tested in accordance with Table 2. Maintain a minimum inlet pressure of 10 psi (69.0 kPa) greater than the allowable pressure loss at rated flow. Purge the system of air. Gradually increase the flow of water through the
