UL-1696:2015 pdf free download – STANDARD FOR SAFETY Mechanical Protection Tubing (MPT) and Fittings.
6.2 Conditioning
6.2.1 Nonmetallic and composite MPT, fittings and clamps shall be conditioned for not less than 24 h at
23 ±2°C (73 ±4°F) and 50 ±5% relative humidity before being tested under the same conditions.
6.3 Identification of materials
6.3.1 Appropriate specimens of each nonmetallic material employed in the construction of nonmetallic
MPT, composite MPT and nonmetallic and composite fittings shall be subjected to the Infrared
Spectroscopy (IR) test, as specified in UL 746A or CAN/CSA C22.2-No. 0.17.
6.4 Vertical flame
6.4.1 Three samples each of the smallest, intermediate, and largest size of nonmetallic MPT and composite MPT and fittings in a range shall be separately subjected to two 15 s applications of flame, the period between applications being 15 s. If a range of colors is available, samples in accordance with Clause 6.4.2 shall be tested. The tubing shall be tested in accordance with Clauses 6.4.7 to 6.4.14. A fitting shall be tested in accordance with Clauses 6.4.7 to 6.4.9 and 6.4.12 to 6.4.14. See Figure 1 for essential dimensions for positioning tubing for the vertical flame test. See Figure 2 for essential dimensions for positioning a fitting for the vertical flame test.
6.4.2 Specimens of the lightest and darkest colors in the color range shall be provided. When a color in the range contains certain pigments which are known to affect flammability characteristics, specimens of that color shall also be provided. If a range of colors are not desired or available testing of a specific color is only considered representative of that color.
6.4.3 The MPT shall not be acceptable if it:
a) Continues to flame longer than 60 s after the second application of the flame;
b) Shows more than 25% of the indicator flag burned away or charred after the first or second application of the flame. Soot that can be removed with a cloth or the fingers and brown
scorching shall be ignored; or
c) Emits flaming or glowing particles or flaming drops at any time that ignite the cotton on the burner, wedge, or floor of the enclosure. Flameless charring of the cotton shall be ignored.
6.4.4 The fitting shall not be acceptable if it:
a) Continues to flame longer than 60 s after the second application of the flame; or
b) Is completely consumed.
6.4.5 The nonmetallic or composite MPT need not be subjected to this test if:
a) It is made of a material that is designated V-0 or V-i (small-scale flame test rating), in
accordance with UL 94 or CAN/CSA-C22.2 No. 0.17; and
b) Its minimum thickness is at least the same thickness as the material qualified as V-0 or V-i.
6.4.7 This test shall be performed on specimens after conditioning, in accordance with Clause 6.2, in a 3-sided metal enclosure in an exhaust hood or cabinet. The metal enclosure shall be 305 mm (12 in) wide, 355 mm (14 in) deep, 610 mm (25 in) high, and the top and front shall be open. A 457 mm (18 in) specimen cut from a length of finished nonmetallic MPT shall be secured at both ends with its longitudinal axis vertical in the center of the enclosure. A fitting shall be secured with its longitudinal axis vertical in the center of the enclosure.