UL-536:2014 pdf free download – STANDARD FOR SAFETY Flexible Metallic Hose.
11 Temperature Test
11 .1 Hose shall not leak when pressurized as specified in 11.3 after being exposed to an elevated temperature specified in 11.2.
11 .2 One sample of intermediate length of each diameter is to be used in this test. Each sample is to be exposed in a circulating air oven at 450°F (232°C) for 100 hours.
11.3 At the end of the oven exposure, the sample is to be cooled to room temperature and is then to be subjected for 1 minute to a hydrostatic pressure of 1-1/2 times the maximum rated pressure.
12 Flame Test
12.1 Hose shall not leak or show evidence of damage when pressurized as specified in 12.5 and 12.6 after being subjected to the flame test specified in 12.2 — 12.4.
12.2 One sample of each diameter and at least 12 inches (305 mm) long between couplings is to be used in this test. A lineal section of 6 inches (152 mm) is to be suspended horizontally at a vertical distance of
3 inches (76.2 mm) above and parallel to a strip pipe gas burner.
12.3 The burner is to be constructed of 3/4 inch Schedule 40 iron pipe (Standard for Welded and Seamless Wrought Steel Pipe, ANSI/ASME B36.1OM) having a straight line of 1/16 inch (1.6 mm) drilled ports, on 1/2 inch (12.7 mm) centers, located along the top for a distance of 8 inches (203 mm). A gas pressure equal to 1 inch (25.4 mm) water column is to be maintained in the pipe when gas equivalent to natural gas having approximately 1000 Btu per cubic foot (37.3 MJ/m3) is employed.
12.4 The flame resulting from this apparatus is to burn under at least 6 inches (152 mm) of the exposed length of hose and under one coupling or union at one end. The sample is to be exposed to the flame for 5 minutes.
12.5 At the end of the flame exposure, the sample is to be cooled to room temperature and is then to be subjected for 1 minute to a hydrostatic pressure of 1-1/2 times maximum rated pressure.
12.6 The pressure is then to be increased to five times maximum rated pressure and then immediately released.
13 Compression Test
13.1 Hose shall not leak when subjected to the pressure specified in 13.4 after being subjected to an external load specified in 13.3.
13.2 One sample of intermediate length of each diameter is to be used in this test. A hydrostatic pressure of 25 psig (172 kPa) is to be maintained within the sample when under test.
13.3 With the sample supported uniformly along its length, a load of 1000 pounds (4448 N) is to be successively applied by a flat metal surface over a distance of 1 inch (25.4 mm) along the length of the hose at three equally spaced locations. The load at each location is to be maintained for 1 minute.
13.4 The sample is then to be subjected for 1 minute to a hydrostatic pressure of five times the maximum rated pressure.
14 Bending Test
14.1 Hose shall not leak when pressurized as specified in 14.4 after being subjected to repeated bending specified in 14.2 and 14.3.
14.2 One sample of each diameter of a length suitable for bending is to be used in this test. The sample is to be supported uniformly along its length, as on a table.
14.3 The sample is to be bent and straightened 50 times to an arc of 45 degrees having a radius of 60, then 50, then 40, and 30 percent of the minimum radius of bend as specified in 5.2. The 50 cycles of bending and straightening is to be completed for each radius before bending at the next lower radius is commenced.
14.4 Upon completing 50 bends at 30 percent of the minimum bend radius the sample is then to be subjected for 1 minute to a hydrostatic pressure of 1-1/2 times the maximum rated pressure.