ASME A112.18.3:2002 pdf free download

ASME A112.18.3:2002 pdf free download.PERFORMANCE REQUIREMENTSFOR BACKFLOW PROTECTION DFVICES AND SYSTEMS INPLUMBING FIXTURE FITTINGS.
Two sample sets, each consisting of a minimum of seven specinwns. shall be evaluated for durability by tests defined in para 15. At thc start of the evaluation. both sets samples shall be tested fur functional performance (para. 11). Thereaftei one sample set shall be tested for mechanical wear and mineral deposition (para. 15.2). and the second sample set shall be tested for aging and corrosion (para. 151). When retested, there shall be a maximum of three incremental increases.
7.3 Conformance
Any physical damage to internal devices known to preclude functional performance shall be cause for reection. The allowable failures shall not exceed the values shown in Table I.
8 FIXTURE FITTINGS WITH INTERNAL DEVICES COMPLYING WITH PARAS. 6 AND 7
The purpose of this paragraph is to define 11w requirements and test procedures For the evaluation of finished products incorporating certified backliow protection devices which have been demonstrated to be in compliance with paras. 6 and 7 of this Standard.
8.1 Health and Safety
8_i_i Thercshallbeatleasliwobaekulow prevention devices, in series proven by tests as in compliance with para. 7 of this Standard. They shall operate independentlv as integral parts of the fixture fitting. At least one device shall be a check valve, called the primary check in this Standard.
Among the protection devices are
(a) check valves
(b) vents to air
(c) vacuum breakers
(d) automatic diverters
8J.2 Contaminants shall not enter the potable water system through backflow nor shall contaminants be allowed to enter the fitting beyond the First barrier when the backflow preventer is operating properly. The test shall be in accordance with para. 12.
8.1.3 The manufacturer shall specify the type and location of the hackflow protection system in the product literature or in the installation instructions.
8.2 Performance Tests
8.2.1 SelectIon of Test Specimens. To comph with this Standard, two specimens will be selecied at random from a lot of five production fittings. liefore mounting the fIxture fittings in the test rig, correct installation of maximum opening pressure, the minimum flow rate at25 in.Hg (84 kPa gage), and the corresponding pressuredrop (vacuum gauge reading).
An increase in pressure drop or reduction in air flowrate larger than 20%after completion of the durabilitytests shall be cause for rejection.
12FUNCTIONAL TEST OF BACKFLOW PREVENTION SYSTEMS
12.1 Back Pressure
Mount the fixture fitting as received from the manu-facturer in its normal position in accordance with theinstallation instructions.