UL 536-2019 pdf download

UL 536-2019 pdf download.Flexible Metallic Hose.
5.3 In the tests, if samples of each diameter are specified and the product is made in more than four diameters, the samples may be limited to four diameters considered to be representative of the line. If samples are specified for tests involving bending of the sample, the length of sample is to be such that the hose may be bent over an arc of at least 45 degrees with the radius of curvature designated for the test. If samples are specified to be the shortest, they are to be prepared using the minimum length to be designated by the manufacturer as indicated in 5.1 (b) or the shortest length the test equipment is capable of testing, whichever is longer. Tests are generally to be conducted in the order in which they are presented, using new samples for each test. If a manufacturer desires to reduce the number of samples, tests such as the Temperature Test, Section 11, and Flame Test, Section 12, may be conducted using samples previously subjected to other tests, such as the Hydrostatic-Strength Test, Section 6. 6 Hydrostatic-Strength Test 6.1 A hose assembly of length sufficient to make a 90 degree bend based on the radius of curvature as specified in 5.2 and Table 5.1 is to be used in this test. The hose shall not leak nor rupture when subjected for 1 minute to a hydrostatic pressure equivalent to five times its maximum rated pressure. 6.2 One sample of each diameter of a length acceptable for bending in accordance with 5.2 is to be used in this test. The sample is to be installed in a straight line, with one end attached to the pressure source and other end plugged and free. 6.3 The pressure is to be uniformly raised to 1-1/2 times rated pressure and maintained at that pressure for 1 minute. The hose is then to be bent 90 degrees with a radius of curvature as specified in 5.2 and the pressure maintained for one additional minute. 6.4 With the hose maintained in the bent position, the pressure is then to be increased to five times the maximum rated pressure for 1 minute.
7.2 Two samples of the shortest length of each diameter are to be used in this test. One sample of each diameter is to be installed in a vibration machine in a straight line. The other sample of each diameter is to be similarly installed, except that it is to be bent with a radius of curvature as specified in 5.2. 7.3 The vibration machine is to provide means for applying hydrostatic pressure to any one end of the sample, and that end is to be mounted so as to be stationary. The opposite end of the sample is to be plugged and subjected to a motion in one plane. The motion is to have a displacement of 0.15 inch (3.81 mm). 7.4 The maximum rated pressure is to be maintained in the sample during the period of vibration. The sample is to be vibrated at the rate of 900 to 1000 cycles per minute. 7.5 The sample is to be subjected to vibration for 300 hours, after which the hydrostatic pressure is to be increased to 1-1/2 times maximum rated pressure and then immediately released. 8 Flexure Test 8.1 Hose shall not leak or show evidence of damage when pressurized as specified in 8.4 and 8.5 and exposed to 20,000 cycles of flexing in one plane through an appropriate radius of curvature. 8.2 Two samples of each diameter of a length suitable for bending are to be used in this test. Each sample is to be installed in a motion machine capable of bending the hose from a straight-line position through an arc of 45 degrees in one plane with a radius of curvature as specified in 5.2. 8.3 The motion machine is to provide means for applying hydrostatic pressure to one end of the sample, and that end is to be mounted so as to be stationary. The opposite end of the sample is to be plugged. 8.4 The maximum rated pressure is to be maintained in the sample while it is being flexed at the maximum rate of 10 cycles per minute for a total of 20,000 cycles. 8.5 At the end of the cycling period, the hydrostatic pressure is to be increased to 1-1/2 times maximum rated pressure and then immediately released. UL 536-2019 pdf download.