1、Performance Requirements for Dual Check Backflow PreventersASSE InternationalASSE Standard #1024-2017ASSE Board Approved: January 2018ANSI Approved: January 2018 ICS Code: 23 060 5091 140 60An American National StandardDual Check Backflow Preventers iASSE Standard #1024-2017ASSE InternationalMokena,
2、 IllinoisCopyright 2018, 2004, 1994, 1988, 1979All rights reserved.Neither this standard, nor any portion thereof, may be reproduced without the written consent of ASSE International.No product may be said to be listed by ASSE unless the manufacturer has applied to ASSE International, has had its pr
3、oduct tested by an official ASSE recognized independent laboratory according to the applicable standards, and had its documentation reviewed and approved by the consensus ASSE Seal Control Board. Having completed the aforementioned, the manufacturer may display the ASSE seal on the product. Instruct
4、ions for receiving the authorization to display the Seal are available from the ASSE International office. Organizations wishing to adopt or list any ASSE standard should print the ASSE standard number on the cover page first in equal or larger type to that of the adopting or listing organization.Ge
5、neral Informationii Dual Check Backflow Preventers ASSE Standard #1024-2017Dual Check Backflow Preventers iiiASSE Standard #1024-2017This foreword shall not be considered a part of the standard; however, it is offered to provide background information.ASSE International is dedicated to the preservat
6、ion of public health and safety through its guiding principle, “Prevention Rather Than Cure.” Preventing the contamination of potable water in plumbing systems is a major objective of ASSEs Standards Program.The recognition of probable sources or causes of contamination or pollution of a potable wat
7、er system whereby it becomes unfit or undesirable for human consumption is vital 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 wit
8、hin the premises supplied, which could be a source of contamination or pollution, 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
9、 protects the vendors or public water supply only. It does not provide protection within the premises supplied.In modern plumbing systems, there are many situations where backflow could occur due to backpressure conditions. In some cases, the backflow of pollutants into the potable water system coul
10、d cause serious health hazards, while in other cases the backflow of pollutants 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 devices know as dual check valves, which will fulfill “low hazard” prote
11、ctive needs.The devices described are suitable for either protection by 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.These devices are generally suitable for cold water servi
12、ce under continuous or 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 ASSEs backflow prevention standards. Each standard
13、 covers a different 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.This standard was promulgated in accordance with procedures developed by the American National
14、Standards Institute (ANSI).Compliance with this standard does not imply acceptance by any code group unless the standard has been adopted by the code.Forewordiv Dual Check Backflow Preventers ASSE Standard #1024-2017Ed Lyczko, ChairpersonCleveland Clinic Retiree Cleveland, OHWilliam Briggs Jr.MGJ As
15、sociatesNew York, NYTerry BurgerNSF InternationalYpsilanti, MIWilliam ChapinProfessional Code Consulting, LLCCullman, ALMark E. FishZurn Industries, LLCCary, NCRon GeorgePlumb-Tech Design & Consulting Services, LLCNewport, MIDaniel GleibermanSloanLos Angeles, CAChris HaldimanWatts Water Technologies
16、Springfield, MO2017 Product Standards CommitteeJohn F. Higdon, P.E.Apollo Valves / Conbraco Industries, Inc.Matthews, NCConrad Jahrling (non-voting)ASSE InternationalChicago, ILPeter MarzecUnited Association of Plumbers and PipefittersPearl River, NYThomas PitcherelloState of New JerseyBordentown, N
17、JDaniel RademacherPlumbing Code and Design Consulting Butte, MTShabbir RawalpindiwalaKohler CompanyKohler, WIBilly SmithASPEMontgomery, ALTsan-Liang Su, PhDStevens Institute of TechnologyHoboken, NJ Dual Check Backflow Preventers vASSE Standard #1024-2017Bill Chapin, ChairpersonProfessional Code Con
18、sulting, LLCCullman, ALChris CorralZurn-WilkinsPaso Robles, CAStephen CrawfordMueller Co.Decatur, IL1024 Working GroupDoug FranklinReliance Worldwide CorporationCullman, AL Conrad L. Jahrling (non-voting)ASSE Staff EngineerChicago, ILDuncan LiangCSA GroupGuangzhou, China vi Dual Check Backflow Preve
19、nters ASSE Standard #1024-2017Table 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
20、Connection Torque 3Table 1 . 33.2 Deterioration at Maximum Rated Temperature and Pressure . 4Figure 1 . 4Table 2 . 43.3 Hydrostatic Test of Complete Device . 5Figure 2 . 53.4 Hydrostatic Leakage Tests of Check Valves 5Figure 3 . 63.5 Flow and Pressure Loss 6Table 3 . 63.6 Drip Tightness of Check Val
21、ves . 73.7 Check Valve Operation 73.8 Dual Check Valve Integrity at Minimum Intermittent Rated Flow . 8Table 4 . 8Section IV 94.0 Detailed Requirements 94.1 Materials 94.2 Repairability . 104.3 Instructions for Marking and Installation 10Section V 115.0 Definitions . 11Dual Check Backflow Preventers
22、 1ASSE Standard #1024-2017Performance Requirements for Dual Check Backflow PreventersSection I1.0 General 1.1 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 flowing b
23、ack 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 outle
24、ts. These devices are intended for continuous or intermittent pressure conditions with cold water service. 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 force lo
25、aded 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: NPS, NPS, NPS, NPSM, NPS, NPS, 1 NPSM, 1 NPS, 1- NPSM, 1- NPS, 1- NPS, and 2 NPS
26、(8 DN, 10 DN, 15 DN, 18 DN, 20 DN, 25 DN, 32 DN, 40 DN, and 50 DN).1.2.3 Pressure RangeThe device shall be designed for a working pressure of up to a minimum of 160 psi (1103 kPa).1.2.4 Temperature Rangea) Cold water service ranges from 40.0 F to 110.0 F (4.4 C to 43.3 C), or the manufacturers maxim
27、um 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.1.2.5 Flow CapacityThe device shall meet the minimum water flow capacities at or below the maximum pressure loss speci
28、fied in Section 3.4.1.4 Reference StandardsReferences to industry standards shall mean the edition referenced below. ASME B1.20.1- 2013, Pipe Threads, General Purpose, Inch ASME B1.20.3-1976 (R2013), Dryseal Pipe Threads, Inch AWWA C700-15, Cold Water Meters Displacement Type, Metal Alloy Main Case
29、UL 969-2017, Marking and Labelling Systems2 Dual Check Backflow Preventers ASSE Standard #1024-2017Section II2.0 Test Specimens2.1 Samples Submitted for TestThree devices of each model and size shall be submitted by the manufacturer. Tests shall be performed in the order listed on one device.2.2 Sam
30、ples TestedThe testing agency shall select one of each model and size for full test.2.3 DrawingsAssembly and installation drawings and other data needed to enable a testing agency to determine compliance with this standard shall accompany devices submitted for examination and performance testing und
31、er this standard.2.4 RejectionFailure of one (1) device shall result in a rejection of that model and size.Dual Check Backflow Preventers 3ASSE Standard #1024-2017Section III3.0 Performance Requirements and Compliance Testing3.1 Connection Torque3.1.1 PurposeThe device shall be capable of withstandi
32、ng, without deformation, breakage or leakage, the axial torque exerted at the end connection of the device to the pipe line per Table 1.3.1.2 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 tha
33、n 5 minutes. The device shall be pressurized at 160 psi 2 psi (1103 14 kPa) or the manufacturers maximum rated working pressure 2 psi ( 14 kPa), whichever is greater, during the torque test.Table 1 Water Meter Connection SizeNominal Pipe SizeMaximum TorqueNPSM NPS DN in-lbf N-m 8 150 (17.0) 10 200 (
34、22.6) 15 300 (33.9) 18 300 (33.9)1 20 450 (50.8)1- 1 25 450 (50.8)1- 32 585 (66.1)1- 40 720 (81.3)2 50 960 (108)3.1.3 CriteriaAny indication of damage that prevents full compliance with any part of this standard shall result in the rejection of the device.3.2 Deterioration at Extremes of Manufacture
35、rs Temperature and Pressure 3.2.1 PurposeThe purpose of this test is to evaluate the materials performance at extremes in temperature and pressure. The geometry of any material shall not be adversely affected when exposed to water at the extremes of the manufacturers temperature and pressure ranges.
36、4 Dual Check Backflow Preventers ASSE Standard #1024-20173.2.2 Procedure3.2.2.1 Cold Water DevicesCold water devices shall be tested at 40.0 F 5 F and 110.0 F 5 F (4.4 C 2.8 C and 43.3 C 2.8 C), or the manufacturers maximum rated temperature, whichever is greater, and the manufacturers maximum rated
37、 pressure.3.2.2.2 Hot Water DevicesHot water devices shall be tested at 40.0 F 5 F and 180.0 F 5 F (4.4 C 2.8 C and 82.2 C 2.8 C) or the manufacturers maximum rated temperature, whichever is greater, and the manufacturers maximum rated pressure.3.2.2.3 ProcedureInstall the device as shown in Figure
38、1. A recirculating system shall be permitted to be used instead of the vented reservoir at the option of the testing laboratory.Water at the pressure and lower temperature per either section 3.2.2.1 or 3.2.2.2 shall be circulated through the device continuously for 80 hrs. Repeat at the higher tempe
39、rature of either section for 80 hrs. If this time interval is not possible, the minimum continuous run time shall be 8 hrs such that the cumulative run time is 80 hrs. The device shall be insulated to maintain the required temperature through the device.Figure 1FlowmeterPressure gaugeOutletInletHot
40、water supplyCold water supplyDeviceThermometerVented reservoir orrecirculating tankTable 2Water Meter Connection SizeNominal Pipe SizeMinimum Hot Water FlowNPSM NPS DN GPM L/min 8 1.5 (5.7) 10 3.0 (11.4) 15 5.0 (18.9) 18 5.0 (18.9)1 20 7.0 (26.5)1- 1 25 8.0 (30.3)1- 32 9.0 (34.1)1- 40 10.0 (37.9)2 5
41、0 15.0 (56.8)Dual Check Backflow Preventers 5ASSE Standard #1024-20173.2.3 CriteriaAny indication of change in physical characteristics of the materials that prevents full compliance with all requirements of this standard shall result in the rejection of the device.3.3 Hydrostatic Test of Complete D
42、evice3.3.1 PurposeThe purpose of this test is to demonstrate the devices ability to withstand a pressure of 320.0 psi (2206 kPa) or two (2) times the manufacturers maximum rated working pressure, whichever is greater.3.3.2 ProcedureInstall the device as shown in Figure 2. Purge the system of air and
43、 pressurize it to the test pressure. Maintain the pressure for 10 minutes. Observe for external leaks or other indications of damage.Figure 2FlowmeterV1 V2V3V4V5 V6Pressure gauge Pressure gaugeSupply DeviceDrainDrainSight glass10 pipe diameters5 pipe diametersTest setup for sections 3.3, 3.4, 3.5, 3
44、.6, and 3.8Note: for hydrostatic pressures in sections 3.3 and 3.4, the supply upstream of the initial shut-off valve may be supplied using a device such as a hand pump.3.3.3 CriteriaAny leaks shall result in the rejection of the device. Any damage that prevents compliance with any part of this stan
45、dard shall also result in the rejection of the device.3.4 Hydrostatic Leakage Tests of Check Valves3.4.1 PurposeThe purpose of this test is to determine whether leaks or damage occurs when the device is subjected to 320 psi (2206 kPa), or two (2) times the manufacturers maximum rated working pressur
46、e, whichever is greater, applied to the downstream side of each check valve individually.3.4.2 Procedure3.4.2.1 Upstream Check ValveInstall the device as shown in Figure 2. Hold the downstream check valve partially open (fully clear of its seat). Purge the device of air, close the supply valve, open
47、 the shut-off cock to the 6 Dual Check Backflow Preventers ASSE Standard #1024-2017sight glass. Adjust the water level in the sight glass to be 0.50 in (13 mm) above the highest level of the device. Raise the pressure on the downstream side of the check valve to 320 psi (2206 kPa) or two (2) times t
48、he manufacturers maximum rated working pressure of the device, whichever is greater, and record the water level in the sight glass. Hold for 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 device.3
49、.4.2.2 Downstream Check ValveRepeat the test with the upstream check valve held partially open (fully clear of its seat), the downstream check in a fully closed position, and a pressure of 320 psi (2206 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 5 minutes and observe for indication of damage or leakage by the check v
