1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULAugust 14, 20171UL 2573Outline of Investigation for Automatic Air Release, Air/Vacuum andCombination Air Valves for Fire Protection ServiceIssue Number: 2August 14, 2017Summary of TopicsThis seco
2、nd issue of the Outline of Investigation for Automatic AirRelease and Air/Vacuum Valves for Fire Protection Service, Subject 2573,includes requirements for combination air valves for dry standpipesystems such as those referenced in NFPA 502, Standard for RoadTunnels, Bridges, and other Limited Acces
3、s Highways.ULs Outlines of Investigation are copyrighted by UL LLC. Neither a printed norelectronic copy of an Outline of Investigation should be altered in any way. All ofULs Outlines of Investigation and all copyrights, ownerships, and rights regardingthose Outlines of Investigation shall remain t
4、he sole and exclusive property of ULLLC.COPYRIGHT 2017 UL LLCUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULAUGUST 14, 2017UL 25732No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERM
5、ISSION FROM ULCONTENTSINTRODUCTION1 Scope .42 Units of Measurement .43 Components 54 References .55 Glossary .5CONSTRUCTION6 General 67 Rated Pressure .68 Materials .6PERFORMANCE9 General 710 Leakage Test 711 Hydrostatic Strength Test .812 Cycling Test .813 Clogging Test .814 Elastomeric Parts (Exce
6、pt Gaskets) Test .915 Plastic Components Impacting Valve Operation 1015.1 Air oven aging .1015.2 Water aging .10MANUFACTURING AND PRODUCTION TESTS16 General 1117 Production Leakage Tests .11MARKINGS18 General 12INSTALLATION INSTRUCTIONS19 General 12AUGUST 14, 2017 UL 2573 3UL COPYRIGHTED MATERIAL NO
7、T AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULINTRODUCTION1 Scope1.1 These requirements cover automatic air release (vents), air/vacuum valves and combination airvalves intended for fire protection service.1.2 Automatic air release valves for use in wet pipe automati
8、c sprinkler systems are intended forinstallation in a sprinkler branch line when it is desired to evacuate air from portions of the sprinkler pipingsystem.1.3 Automatic air release valves for use with fire pumps are intended for installation on the fire pump tovent entrapped air.1.4 Automatic air/va
9、cuum valves equipped with throttling devices are intended for use with vertical turbinepumps. These valves are intended to release large volumes of air in a controlled manner upon pumpstart-up to reduce air related surges and admit air after shutdown, to minimize the development of vacuumconditions
10、within the pump.1.5 Combination air valves equipped with throttling devices are intended for use in dry standpipe andsimilar applications where the (1) release of large volumes of air in a controlled manner is needed, (2)continuous release of air within the system is needed while the system is press
11、urized and (3) admissionof air into the system is needed to minimize the development of vacuum conditions when the system isshutdown.1.6 Requirements for installation of sprinkler systems are included in the Standard for the Installation ofSprinkler Systems, NFPA 13. Requirements for installation of
12、 devices on fire pumps are included in theStandard for the Installation of Stationary Pumps for Fire Protection, NFPA 20. Requirements for theinstallation of dry standpipe systems are included in standards such as the Standards for the Installationof Standpipe and Hose Systems, NFPA 14 and Road Tunn
13、els, Bridges, and other Limited AccessHighways, NFPA 502.2 Units of Measurement2.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory orapproximate information.AUGUST 14, 2017UL 25734UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUT
14、ION WITHOUT PERMISSION FROM UL3 Components3.1 Except as indicated in 3.2, a component of a product covered by this Outline of Investigation shallcomply with the requirements for that component.3.2 A component is not required to comply with a specific requirement that:a) Involves a feature or charact
15、eristic not required in the application of the component in theproduct covered by this Outline of Investigation, orb) Is superseded by a requirement in this Outline of Investigation.3.3 A component shall be used in accordance with its rating established for the intended conditions ofuse.3.4 Specific
16、 components are incomplete in construction features or restricted in performance capabilities.Such components are intended for use only under limited conditions, such as certain temperatures notexceeding specified limits, and shall be used only under those specific conditions.4 References4.1 Any und
17、ated reference to a code or standard appearing in the requirements of this Outline ofInvestigation, shall be interpreted as referring to the latest edition of that code or standard.5 Glossary5.1 For the purpose of this outline, the following definitions apply.5.2 AUTOMATIC AIR RELEASE VALVE (VENT) A
18、 device designed to automatically vent into theatmosphere entrapped air that may accumulate at localized high points within a pump or sprinkler pipingsystem while the system is under pressure.5.3 AUTOMATIC AIR/VACUUM VALVE A device designed to automatically release and admit largevolumes of air duri
19、ng vertical turbine pump start-up and shutdown.5.4 COMBINATION AIR VALVE A device (single or dual body) having the features of both anautomatic air release valve and an automatic air/vacuum valve.5.5 ORIFICE The opening through which the air is expelled.5.6 RATED PRESSURE The maximum working pressur
20、e intended to be applied to the inlet of thedevice during end use.5.7 THROTTLING DEVICE A device incorporating an adjustable closure element to control therelease of air from an air/vacuum valve.AUGUST 14, 2017 UL 2573 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION W
21、ITHOUT PERMISSION FROM ULCONSTRUCTION6 General6.1 An automatic air release valve shall have a minimum 1/2-inch (12.7-mm) nominal inlet and outletconnection. An automatic air/vacuum valve shall have a minimum 1-1/2-inch (38.1-mm) nominal inlet andoutlet connection. A combination air valve shall have
22、a minimum 1-1/2-inch (38.1-mm) nominal inlet andoutlet connection for the air/vacuum valve feature and a minimum 1/2-inch (12.7-mm) nominal inlet andoutlet connection for the air release feature of the valve.6.2 Threaded connections shall be in accordance with the Standard for Pipe Threads, General
23、Purpose(Inch), ANSI/ASME B1.20.1, or other national pipe thread standards.6.3 Flange dimensions shall comply with the requirements in the Standard for Gray Iron Pipe Flanges andFlanged Fittings (Classes 25, 125, and 250), ANSI/ASME B16.1, or other national pipe flange standards.6.4 An automatic air
24、release valve shall be provided with an orifice size not less than 1/16-inch (1.59-mm)diameter.6.5 An automatic air release valve intended for use on sprinkler branch lines shall be provided with astrainer having a maximum dimension of an opening in the strainer not exceeding 80 percent of theautoma
25、tic air release valves orifice diameter. The surface area of the screen openings shall not be lessthan a ratio of 4 to 1 of the cross-sectional area of a Schedule 40 pipe of the same nominal size as theinlet of the automatic air release valve.6.6 Automatic air/vacuum and combination air valves shall
26、 be equipped with a throttling device to controlthe release of air.7 Rated Pressure7.1 An automatic air release, air/vacuum, or combination air valve shall have a rated pressure of 175 psig(1.21 MPa) or greater.8 Materials8.1 The body of an automatic air release, air/vacuum, or combination air valve
27、 including throttling deviceshall be constructed of a metallic material having corrosion resistance at least equivalent to cast iron.8.2 Metallic seating surfaces used in an automatic air release or air/vacuum valve shall be constructed ofmaterials with corrosion resistance at least equivalent to br
28、ass, bronze, or Series 300 stainless steel.8.3 A strainer for an automatic air release, air/vacuum, or combination air valve shall be constructed ofmaterials having corrosion resistance at least equivalent to brass, bronze or Series 300 stainless steel.AUGUST 14, 2017UL 25736UL COPYRIGHTED MATERIAL
29、NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULPERFORMANCE9 General9.1 Representative samples of each size automatic air release, air/vacuum, or combination air valve areto be subjected to the tests described in these requirements.10 Leakage Test10.1 When tested for
30、 leakage, automatic air releases and air/vacuum valves shall demonstratecompliance with the following requirements:a) An automatic air release valve intended for use in sprinkler system branch lines shall becapable of withstanding without seat or body leakage an internal hydrostatic pressure of:i) 7
31、 psig (48.3 kPa), andii) Two times the rated pressure when applied for a period of 1 minute at eachpressure.b) An automatic air release or air/vacuum valve intended for use on fire pumps shall becapable of withstanding without seat or body leakage an internal hydrostatic pressure of:i) 20 psig (138
32、kPa), andii) Two times the rated pressure when applied for a period of 1 minute at eachpressure.c) The air release and air/vacuum features of a combination air valve shall be capable ofwithstanding without seat or body leakage an internal hydrostatic pressure of:i) 20 psig (138 kPa), andii) Two time
33、s the rated pressure when applied for a period of 1 minute at eachpressure.10.2 A representative sample is to be filled with water in a manner that all entrapped air is vented. Theinlet of the device is to be hydrostatically pressurized at a rate not exceeding 300 psig (2.07 MPa) perminute until the
34、 applicable test pressures specified in 10.1 are achieved. The test sample is to be visuallyexamined for leakage at the specified test pressure.AUGUST 14, 2017 UL 2573 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL11 Hydrostatic Strength Te
35、st11.1 Automatic air releases, air/vacuum, or combination air valves shall withstand, without rupture of theassembly or damage to the float, a hydrostatic pressure applied to the inlet equal to four times the ratedpressure for a period of 1 minute.11.2 A representative sample is to be filled with wa
36、ter in a manner that all entrapped air is vented. Theinlet of the device is to be hydrostatically pressurized at a rate not exceeding 300 psig (2.07 MPa) perminute until the required test pressure in 11.1 is achieved. The test sample is to be visually examined forrupture and after the test; the floa
37、t is to be visually examined for damage or collapse.12 Cycling Test12.1 When subjected to repeated operation of the air release mechanism, automatic air release,air/vacuum, and combination air valves shall demonstrate compliance with the following requirements:a) An automatic air release valve inten
38、ded for use in sprinkler system branch lines shall becapable of withstanding 100 cycles of repeated operation without damage or malfunction, andsubsequently tested to determine compliance with the Leakage Test described in 10.1(a).b) Automatic air releases and air/vacuum valves intended for use on f
39、ire pumps shall becapable of withstanding 5000 cycles of repeated operation without damage or malfunction, andsubsequently tested to determine compliance with the Leakage Test described in 10.1(b).c) Combination air valves shall be capable of withstanding 100 cycles of repeated operation ofboth the
40、air release and air/vacuum features without damage or malfunction, and subsequentlytested to determine compliance with the Leakage Test described in 10.1(c).12.2 The operating mechanism of the automatic air release valve is to be tested in a manner so that it ismoved from the open to the closed posi
41、tion, such as by repeated filling and draining of the valve.13 Clogging Test13.1 An automatic air release, air/vacuum, or combination air valve shall operate as intended and showno evidence of clogging when tested in accordance with 13.2 13.3.13.2 Ten grams of pipe scale are to be introduced into th
42、e body of the test sample as described in Table13.1.AUGUST 14, 2017UL 25738UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULTable 13.1Contaminant for clogging testSievedesignationa, bNominal sieve opening Grams ofcontaminant (5Percent)inch (mm)
43、 Pipe scaleNo. 50 0.0117 (0.297) 2No. 100 0.0059 (0.150) 3No. 200 0.0029 (0.074) 2No. 325 0.0017 (0.043) 3Total 10aSieve designations correspond with those specified in the Standard Specificationfor Wire Cloth and Sieves for Testing Purposes, ASTM E11.bA sieve type intended for this purpose is Cenco
44、-Meinzer, with sieve sizes whichcorrespond with the number designation in this table, and is in compliance withASTM E11; or an equivalent sieve type.13.3 The inlet of a representative sample is to be connected to a 10 ft. (3 m) length of nominal 1/2 inch(12.7-mm) diameter hose or pipe with a shutoff
45、 valve on the opposite end. Initially, the valve with theconnected pipe or hose is to contain air only. The shutoff valve is then to be opened allowing the flow ofwater at a pressure of 100-psig (689 kPa) to enter into the inlet of the hose and test sample. Visualobservations are to be made for any
46、evidence of clogging and proper operation of the test sample.14 Elastomeric Parts (Except Gaskets) Test14.1 An elastomeric part used to provide a seal shall have the following properties when tested asspecified in the Standard for Gaskets and Seals, UL 157:a) For silicone rubber (with a poly-organo-
47、siloxane as its constituent characteristic), a minimumtensile strength of 500 psi (3.4 MPa) and a minimum ultimate elongation of 100 percent.b) For natural rubber and synthetic rubber other than silicone rubber, a minimum tensilestrength of 1500 psi (10.3 MPa) and minimum ultimate elongation of 150
48、percent; or a minimumtensile strength of 2200 psi (15.2 MPa) and a minimum ultimate elongation of 100 percent.c) Those properties relating to maximum tensile set; minimum tensile strength and elongationafter oven aging; and hardness after oven aging, all as specified the Standard for Gaskets andSeal
49、s, UL 157. The maximum service temperature used to determine the oven time andtemperature for oven aging is 60C.14.2 The Standard for Gaskets and Seals, UL 157, provides for the testing of either finished elastomericparts or sheets or slab material. Sheet or slab material is to be tested when the elastomeric parts areO-rings having diameters of less than 1 inch (25.4 mm). The material tested is to be the same as that usedin the product, regardless of whether finished elastomeric parts or sheet or slab material is tested.AUGUST 14, 2017 UL 2573 9UL COPYRIGHTED MATE
