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ASME A112.1.3-2000 pdf download

1 GENERAL 1.1 Scope This Standard establishes physical requirements and methods of testing for air gap fittings for protecting against back siphonage and back pressure backflow. 1.2 Units of Measurement Values are stated in U.S. Customary Units and the International System of Units (SI). The U.S. Customary Units shall be considered as the standard. In this Standard, gallons (U.S. Liquid) per min is abbreviated gpm and liters (metric liquid) per min is abbreviated L/min. 2 REFERENCE STANDARDS The following document forms a part of this Standard to the extent specified herein. The latest issue shall apply. NSF 61, Drinking Water System Components–Health Effects Publisher: National Sanitation Foundation (NSF Interna- tional), 3475 Plymouth Road, Ann Arbor, MI 48105 3 DEFINITIONS The following definitions apply in this Standard. air gap: a vertical distance through the atmosphere between the lowest potable water outlet and the highest level of the source of fluid contamination. air gap fitting: a device with an integral air gap. critical level: the location on an air gap fitting, deter- mined by test, where presence of contaminated fluid not exceeding this elevation will not allow back siphoning. 1 checking member: a device intended to allow flow in one direction and to prevent flow in the opposite direction. 4 REQUIREMENTS 4.1 Performance Tests The air gap fitting shall pass the performance tests as defined in Section 5 of this Standard with all checking members removed. 4.2 Materials The component materials of the portions of air gap fittings designed for the delivery of water from sources that also supply water for human ingestion and are upstream from the air gap openings covered by the scope of NSF 61, section 9, shall conform to NSF 61, section 9 for endpoint devices. Joining and sealing materials used in these same portions of air gap fittings shall conform to NSF 61, section 6 for joining and sealing materials. Solders and fluxes containing lead in excess of 0.2% by mass shall not be used where they will be in contact with potable water. Metal alloys in contact with potable water shall not exceed 8% lead. 5 TESTING 5.1 Critical Level 5.1.1 With the device installed in accordance with Fig. 1 and with the manufacturer’s installation instruc- tions, submerge the device for at least 1 min, agitating the device during submersion so that all of its openings and exterior and interior surfaces are thoroughly wetted and to remove entrained air.
5.1.3 The manufacturer’s critical level mark on the fitting shall be at or below the critical level determined by this test. 5.2 Back Siphonage 5.2.1 Test Method. The fitting shall be installed in accordance with Fig. 1 and with the manufacturer’s instructions and submerged to the manufacturer’s critical level mark. The following vacuum loads shall be applied in the sequence listed and the presence of water in the sight tube, if any, shall be noted: (a) A vacuum of 25 in. Hg (85 kPa) shall be applied and held for a period of five (5) min. (b) The vacuum shall be raised from 0 to 25 in. Hg (85 kPa), then shall be reduced to 0. (c) A surge effect shall be created by operating a valve which travels between closed and fully open within 2 sec. The applied vacuum shall vary between 0 and at least 25 in. Hg (85 kPa). (d) For devices with multiple water inlets, tests 5.2.1(a), (b), and (c) shall be conducted on the inlets individually. The conditions at the other inlets are to include: water flowing at the manufacturer’s rated maximum, the inlet blocked, and the inlet open to atmosphere. The test matrix is to include these three conditions existing at all possible location combinations. 5.2.2 Any entrance of water in the sight tube shall be cause for the rejection of the fitting. 5.3 Back Siphonage Cross Flow Test for Fittings With Multiple Inlets 5.3.1 Test Method. Each water inlet of a device with multiple water inlets is to be individually tested as follows. The inlet is to be connected to a vacuum source with a sight tube in accordance with the dimen- sions in Fig. 1 and a continuing vacuum of at least 25 in. Hg (85 kPa) applied while specific combinations of water flows are present at the other inlets. Test installation is to be in accordance with the manufactur- er’s instructions. The test matrix is to include all combinations of the water flow increments listed below, also including zero flow.

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