ASME A112.1.3:2000 pdf free download AIR GAP FITTINGS FOR USE WITH PLUMBING FIXTURES, APPLIANCES, AND APPURTENANCES
5.1.2 Lower the water level so that it is no more than 0.12 in. (3 mm) below the highest level of air port opening, and apply a continuing vacuum of at least 25 in. Hg (85 kPa) while the water level is gradually lowered further. The elevation at which si- phonage ceases shall be recorded. A continuing vacuum of 25 in. Hg (85 kPa) shall then be applied as the water level is gradually raised. The elevation at which back siphonage begins shall be recorded. The lower of the two elevations shall be considered the critical level.
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
(e) 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 dimensions 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 manufacturer’s instructions. The test matrix is to include all combinations of the water flow increments listed below, also including zero flow. These tests shall include the following increments of water flow: 0.031 gpm (0.117 L/min) for maximum rated flow of less than 1 gpm (3.785 L/min); 0.5 gpm (1.892 L/min) for maximum rated flow between 1 and 10 gpm (3.785 and 37.85 L/min); 2 gpm (7.570 L/min for flow rated from greater than 10 gpm (37.85 L/min) up to 20 gpm (75.70 L/ min); and 5 gpm (18.92 L/min) for flow rated greater than 20 gpm (75.70 L/min).
5.3.2 Any entrance of water into the sight tube shall be cause for rejection of the device.
5.4 Back Pressure Test
5.4.1 This test shall be conducted on air gap fittings which are rated by their manufacturer to protect against backflow into the outlet of the fitting. With the fitting installed in accordance with the manufacturer’s installation instructions, the manufacturer’s maximum rated back pressure or backflow shall be applied. The flow shall be maintained at least 20 sec after the height of back flowing water stabilizes. Verify that during this test that the water does not rise above the manufacturer’s critical level mark on the fitting. 3
5.4.2 Water above the critical level mark shall be cause for rejection of the fitting.
6 MARKINGS
Air gap fittings shall be permanently marked with the following information:
(a) the manufacturer’s name or trademark.
(b) the manufacturer’s model number.
(c) the manufacturer’s critical level mark.
(d) “inlet” or “outlet” or flow direction. If the fitting has multiple inlets, all inlets shall be marked.
ASME A112.1.3:2000 pdf free download
