UL 109 2020 pdf download – Tube Fittings for Flammable and Combustible Fluids, Refrigeration Service, and Marine Use.
5.2 A Marine-Use fitting and component part shall have less than 38 percent zinc content or include inhibitors to attain equivalent resistance to dezincification. Metals shall be machined, forged, or extruded and shall be designed for use in salt atmosphere and shall not be affected significantly by submersion in salt bilge water. 5.3 Fittings for gas and refrigeration service shall be machined, forged, or extruded. 5.4 With reference to 5.2 and 5.3, the fitting shall be capable of withstanding, without cracking, the i Moist Ammonia Air Stress Cracking Test, Section 11, for copper and copper alloys. 5.5 Carbon steel shall have a protective coating equivalent to that afforded by a cadmium or zinc plating 0.0002 inch (0.005 mm) in thickness plus a chromate treatment or phosphate coating. 5.6 Carbon steel and stainless steel Marine-Use fittings for use with seamless steel tubing in diesel engine fuel systems shall be resistant to corrosion in salt atmosphere. Stainless steel fittings shall have corrosion resistance equivalent to that of stainless steel No. 304. 5.7 The composition of metal alloys used for the fabrication of Marine-Use fittings shall be of known characteristics for normal corrosion resistance, dezincification resistance, and galvanic compatibility with other parts of the fuel system. The material shall be tested, when required, by a salt water atmosphere exposure test. The test is to be conducted for 500 hours. 5.8 Fittings shall be fabricated of a material having a melting point (solidus temperature) not less than 950°F (510°C). 5.9 Brazing material if used, shall have a melting point (solidus temperature) in excess of 1000° F (537°C). Exception: Marine use fittings if soldered, shall be soldered or brazed with a material having a melting point exceeding 840°F (450°C), in accordance with the Standard for Pleasure and Commercial Motor Craft, NFPA 302.
8 Vibration Test 8.1 A tube fitting for other than Marine-Use shall be capable of withstanding exposure to vibration of an amplitude of 1/8 inch (3.2 mm) and a frequency of 1000 vibrations per minute for a period of not less than 30 consecutive hours without development of physical weakness which is capable of impairing its normal service. In evaluating a fitting subjected to this test, physical failure which requires repair or replacement of the fitting or the tubing within or immediately adjacent to the fitting collar does not comply with this requirement. 8.2 Two samples of each size fitting are to be used for this test. 8.3 For these tests, amplitude is the maximum displacement of sinusoidal motion from position of rest or one-half of the total displacement of the fitting. 8.4 Each end of a length of annealed copper tubing is to be connected, in accordance with the manufacturer’s instructions, to one of the two fittings to be tested. The tubing is to have the wall thickness for the size as indicated in Table 8.1. 8.5 The length of tubing for the test is to be that required to conform to the arrangement for each size as illustrated in Figure 8.1 or Figure 8.2.