1、ASSE Standard #1020-2004ASSE Board Approved: February 2004Performance Requirements for Pressure Vacuum Breaker AssemblyASSE InternationaliPressure Vacuum Breaker AssemblyASSE #1020 - 2004ASSE InternationalMokena, IllinoisCopyright 2004, 1998, 1990, 1989, 1982, 1981, 1976, 1974All rights reserved.Nei
2、ther this standard, nor any portion thereof, may be reproduced without the written consent of 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
3、passed the test, displays the ASSE Seal on the product.Instructions for receiving the authorization 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 o
4、r larger type to that of the adopting or listing organization.General Informationii Pressure Vacuum Breaker AssemblyASSE #1020 - 2004iiiPressure Vacuum Breaker AssemblyASSE #1020 - 2004This foreword shall not be considered a part of the standard, however, it is offered to provide background informat
5、ion.This standard was approved by the Product Standards Committee to extend the ASSE portfolio of standards for back pressure and back-siphonage backflow prevention devices for pipe applied vacuum breakers.For pipe applied service conditions in water supply lines, there are two recognized basic cond
6、itions for which vacuum breakers, anti-siphon type, are needed. These two classifications are atmospheric and pressure type.In one instance, the device is under pressure only when there is a demand for water in the equipment being served. The atmospheric type of device is recommended when the servic
7、e line is under pressure only for short periods of time.For the service conditions where the pressure in the service line must be continuous, a vacuum breaker must be constructed with built-in means to mechanically force the atmospheric air inlet valve to open should a negative pressure (vacuum) be
8、created in the supply line. For this class of service, a “pressure type“ device is recommended for use.ASSE Standard #1020 was originally titled Vacuum Breakers, Anti-Siphon, Pressure Type, and was approved by the ASSE Product Standards Committee, received the concurrence of the ASSE Board of Direct
9、ors, and was issued as an official ASSE standard in November, 1974.During its revision in 1989, the title was changed to Pressure Vacuum Breaker Assembly. This change also included a recommendation for outdoor usage of the assembly.The draft of this Standard was presented to the ASSE Product Standar
10、ds Committee during their regular meeting in 1989. The Committee acted to recommend adoption of this standard to the ASSE Board of Directors, and the Board approved the standard to become effective January 1990. The standard was revised in 1994, and again in 2003.This standard was promulgated in acc
11、ordance with procedures developed by the American National 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 Pressure Vacuum Breaker AssemblyASSE #1020 - 2004Richard J. ProspalProduct Stand
12、ards Committee ChairmanProspal Consulting Services, Inc.Brunswick, OhioRand H. AckroydRand EngineeringNewburyport, MassachusettsMichael BeckwithState of Wisconsin Department of CommerceMadison, WisconsinGunnar O. CollinsCollins Backflow Specialists, Inc.Palatine, IllinoisJud CollinsOklahoma State He
13、alth DepartmentOklahoma City, OklahomaShannon M. Corcoran ASSE Standards CoordinatorWestlake, OhioA. Richard EmmersonGeneral InterestBuffalo Grove, IllinoisSteven HazzardASSE Staff EngineerWestlake, OhioDale HollowaySGS United States Testing CompanyTulsa, Oklahoma2003-04 Product Standards Committee
14、Michael KobelInternational Association of Plumbingand Mechanical OfficialsWalnut, CaliforniaValentine Lehr, P.E.Lehr AssociatesNew York, New YorkPeter MarzecUnited Association ofPlumbers and PipefittersWashington, D.C.Perry W. Meikle, Jr.Perry W. Meikle Consulting EngineerAntioch, CaliforniaShabbir
15、RawalpindiwalaKohler CompanyKohler, WisconsinLynne Simnick International Code Council, Inc.Country Club Hills, IllinoisJack VilendrePrecision Plumbing Products, Inc.Portland, OregonDavid ViolaPlumbing Manufacturers InstituteSchaumberg, IllinoisJoseph C. Zaffuto, P.E.ASSE Staff EngineerWestlake, Ohio
16、vPressure Vacuum Breaker AssemblyASSE #1020 - 2004Rand H. AckroydRand EngineeringNewburyport, MassachusettsGunnar O. CollinsCollins Backflow Specialists, Inc.Palatine, IllinoisRobert CrossHouston Area JATCHouston, TexasBill DunmireFEBCO, Division of SPX Valves and ControlsSt. Pauls, North CarolinaBo
17、b FunderburkConbraco Industries, Inc.Matthews, North CarolinaSteven HazzardASSE Staff EngineerWestlake, OhioJohn HigdonConbraco Industries, Inc.Matthews, North Carolina1020 Working GroupNick NyugenToro CompanyRiverside, CaliforniaBrad NollWilkins, Division of Zurn IndustriesPaso Robles, CaliforniaRo
18、bert PurzyckiBAVCOLong Beach, CaliforniaCarl SchroederPlumbing Industry Training CenterDetroit, MichiganGeorge SwensonFlomatic Valves - Flomatic Corp.Glens Falls, New YorkJoseph C. Zaffuto, P.E.ASSE Staff EngineerWestlake, Ohiovi Pressure Vacuum Breaker AssemblyASSE #1020 - 2004Table of ContentsSect
19、ion I . 11.0 General . 11.1 Application 11.2 Scope . 11.3 Mechanical Function 21.4 Reference Standards . 2Section II 32.0 Test Specimens 32.1 Samples Submitted 32.2 Samples Tested 32.3 Drawings 32.4 Rejection 3Section III . 43.0 Performance Requirements and Compliance Testing 43.1 Hydrostatic Test o
20、f Complete Device . 4Figure 1 43.2 Hydrostatic Test of Check Valve . 4Figure 2A 5Figure 2B 53.3 Rated Flow and Maximum Allowable Pressure Loss . 5Table 2 53.4 Air Inlet Valve Opening Pressure Test 6Figure 3 63.5 Drip Tightness of Check Valve Test 63.6 Air Passage Comparative Areas 7Figure 4 73.7 Bac
21、ksiphonage Test . 8Table 3 8Figure 5 9Figure 6 9Figure 7 93.8 Shock (Water Hammer) Test of the Device 93.9 Deterioration at Extremes of Manufacturers Temperature 103.10 Life Cycle Test . 11Section IV 124.0 Detailed Requirements . 124.1 Materials . 124.2 Instructions for Marking and Installation . 13
22、4.3 Installation and Maintenance Instructions 134.4 Installation Instructions . 13Section V . 145.0 Definitions . 14Pressure Vacuum Breaker AssemblySection I1.0 General1.1 ApplicationPressure Vacuum Breaker Assemblies (herein referred to as “device“) are for installation in water supply lines to pre
23、vent the entrance of non-potable material into the potable water supply by backsiphonage only. It is not for use in any system where backpressure can be applied to the device.When a supply pressure is between 1.0 psi to 2.0 psi (6.9 kPa to 13.8 kPa), the air inlet valve is open and the device will c
24、ontinuously dis charge. Due to this probability of water discharge from the at mospheric air inlet valve, the device shall be installed where water discharge does not cause damage.1.2 Scope1.2.1 DescriptionThe assembly shall contain an independently acting check valve force loaded to the closed posi
25、tion, and an independently acting air inlet valve located downstream of the check valve that is force loaded to the open position. The assembly shall also include two tightly closing shutoffs, one at the inlet of the assembly and one at the outlet of the assembly and two tightly closing test cocks o
26、ne immediately upstream and one immediately downstream of the check valve.Vacuum breakers, other than air gaps, shall be classified into three general types:a. Atmospheric Type (See ASSE Standard #1001);b. Pressure Type (ASSE #1020, as described in this standard); andc. Back Siphonage (See ASSE Stan
27、dard #1056).1.2.2 Size RangeThe device shall be designed to accommodate nominal pipe sizes 1/2 NPS to 2 NPS (15 DN to 50 DN).1.2.3 Working Pressure RangeThe minimum rated working pressure of the device shall not be less than 150.0 psi (1034.3 kPa).1.2.4 Temperature Rangea. Cold water service shall r
28、ange from 33.0 F to 110.0 F ( 0.6 C to 43.3 C).b. Hot water service shall range from 33.0 F to not less than 180.0 F ( 0.6 C to 82.2 C).1Pressure Vacuum Breaker AssemblyASSE #1020 - 20041.3 Mechanical Function1.3.1 Check ValveThe check valves shall be force loaded (biased) to a normally closed posit
29、ion under static conditions.1.3.2 Air Inlet Valvea. The air inlet valve shall be force loaded (biased) to a normally open position when the line pressure is atmospheric. It shall be located above the pipe line so that water can drain from it by gravity.b. The air inlet valve shall start to open when
30、 the line pressure reaches 1.0 psi (6.9 kPa) and the air inlet valve shall be fully open when water drains from the body.1.3.3 Test CocksTest cocks shall be resilient seated, and as part of the device, shall meet all material specifications and hydro static requirements of this standard.Pipe size co
31、nnections of test cocks shall not be smaller than the sizes indicated in Table 1.Table 1Test Cock Sizing1.3.4 Accessibilitya. The check and air inlet valves shall be accessible for inspection, repairs or replacements.b. All replaceable parts of the assemblies of the same size and model shall be inte
32、rchangeable with the original parts.1.4 Reference StandardsReference to industry standards shall mean the latest edition.1/81/4Size of Device Size of Test CockNPS DN 15 - 2532 - 501/2- 111/4- 2NPS DN 6 or SAE82 Pressure Vacuum Breaker AssemblyASSE #1020 - 2004Section II2.0 Test Specimens2.1 Samples
33、SubmittedThree (3) assemblies of each size and model shall be submitted by the manufacturer. Tests shall be performed in the order listed on one (1) device of each size.2.2 Samples TestedThe testing agency shall select one (1) of each size and model for full test.2.3 DrawingsAssembly drawings and ot
34、her data which are needed to enable a testing agency to determine compliance with this standard, together with installation drawings, shall accompany assemblies submitted for examination and performance test under this standard.2.4 RejectionFailure of one (1) device shall be cause for rejection of t
35、hat size and model until the manufacturer has corrected the fault and submitted new assemblies for testing.3Pressure Vacuum Breaker AssemblyASSE #1020 - 2004Section III3.0 Performance Requirements and Compliance Testing3.1 Hydrostatic Test of Complete Device3.1.1 PurposeThe purpose of this test is t
36、o demonstrate the devices ability to withstand a pressure of 300.0 psi (2068.5 kPa), or the manufacturers maximum rated working pressure, whichever is greater, when applied at the inlet.3.1.2 ProcedureInstall the device as shown in Figure 1. Purge the system of air and pressurize to test pressure. M
37、ain tain the pressure for five (5) minutes. Observe the device for external leaks.Figure 13.1.3 CriteriaAny leaks shall result in a rejection of the device.3.2 Hydrostatic Test of Check Valve3.2.1 PurposeThe purpose of this test is to demonstrate that the devices check valve is capable of withstandi
38、ng, without damage, a back pressure of two (2) times the manufacturers maximum rated working pressure or 300.0 psi (2068.5 kPa), whichever is greater, with atmospheric pressure on the up stream side.3.2.2 ProcedureInstall the device as shown in Figure 2A or 2B. Connect the device inlet to a water su
39、pply and the #2 test cock to a source which will produce an adequate hydrostatic pressure. Purge the system of air. Install a sight glass (Figure 3), with a drain cock on test cock #1. Close the #2 shut-off valve and then close the #1 shut-off valve. Open the drain cock under the sight glass and low
40、er the water level in the sight glass to a height corresponding to the top of the device on test. Slowly raise the pressure on the downstream side of the check valve to the required test pressure observing for indications of leakage or damage to the check valve. Maintain this pressure Ring Piezomete
41、rFlow MeterSupply ValveRing PiezometerGaugeThrottling ValveDevicePressure Vacuum As-semblyShut-off Valve #1Shut-off Valve #2Piezometer to be installedper ANSI/ISA S75.02Note: For the rated flow and pressure loss test, a differential pressure indicat-ing instrument shall be permitted to replace gauge
42、s.4 Pressure Vacuum Breaker AssemblyASSE #1020 - 2004for five (5) minutes. The water level in the sight glass shall reach and maintain a steady level.3.2.3 CriteriaAny leak shall be cause for rejection of the device. Any damage that prevents compliance with any part of this standard shall result in
43、a rejection of the device.3.3 Rated Flow and Maximum Allowable Pressure Loss3.3.1 PurposeThe purpose of this test is to determine the minimum water flow capacity at the maximum allowable pressure loss of 10.0 psi (69.0 kPa) across the device.Table 23.3.2 ProcedureThe test system (Figure 1) shall be
44、equipped with means of measuring the rate of flow through the device and indicating or recording pressure loss. Pressure gauges shall be located in accordance with ANSI/ISA S75.02. The supply system shall be capable of supplying a volume of cold water to meet the maximum flow requirements of the dev
45、ice on test while sustaining a steady inlet pressure of not less than twenty-five per cent (25%) of the rated pressure of the device.Purge the air from the system and then open the throttling valve until the minimum required rate of flow is reached or the maximum allowable pressure loss is obtained
46、and record the data observed. Adjust for pressure loss in piping between the gauges and the device on test.Figure 2A Figure 2BSize of Device Rated FlowNPS DN GPM L/m45.4113.6189.3283.9378.5605.612.030.050.075.0100.0160.01/23/41112152025324050 Required Rate of Water Flow forVarious Sizes of Vacuum Br
47、eakers - Pressure Type5Pressure Vacuum Breaker AssemblyASSE #1020 - 20043.3.3 CriteriaPressure loss across the device greater than the maximum allowable pressure loss of 10.0 psi (69.0 psi) plus any adjustments as noted in section 3.3.2 prior to or at the rated flow shall result in a rejection of th
48、e device. See Table 2 for the minimum flow rates.3.4 Air Inlet Valve Opening Pressure Test3.4.1 PurposeThe purpose of this test is to determine if the air inlet valve opens when the line pressure falls to not less than 1.0 psi (6.9 kPa), and is fully open when water drains from the body.3.4.2 Proced
49、ureWith the device installed as shown in Figure 2A or Figure 2B, install a sight glass (Figure 3) in test cock #2. Remove the air inlet valve protective canopy or other shielding means so as to expose the valve for observation. Open the test cock, in which the sight glass is installed, and pressurize the system to close the air inlet valve. Clear any accumulated water from around the well above the air inlet valve. Slowly drain water from the system until the air inlet valve starts to open. Record the water level in the sight glass. It should not be
