UL-331B:2015 pdf free download – STANDARD FOR SAFETY Strainers for Diesel Fuel, Biodiesel Fuel, Diesel/Biodiesel Blends with Nominal Biodiesel Concentrations up to 20 Percent (B20), Kerosene, and Fuel Oil.
6.1.2 Atmospheric corrosion
6.1.2.1 Metallic material used for fluid confining parts shall be resistant to atmospheric corrosion. Ferrous materials of the thickness specified in the following items are acceptable for the preceding when uncoated:
a) A casting having a wall thickness of not less than 1/4 inch (6.4 mm) if shown by production test to be free of leakage, and
b) Fabricated sheet steel parts having a minimum wall thickness of 0.093 inches (2.36 mm).
6.1.2.2 A protective coating shall provide resistance against atmospheric corrosion to a degree not less than that provided by the protective coatings specified in 6.1 .2.3.
6.1.2.3 Cadmium plating shall not be less than 0.0003 inch (0.008 mm) thick, and zinc plating shall not be less than 0.0005 inch (0.013 mm) thick, except on parts where threads constitute the major portion of the area, in which case the cadmium or zinc plating shall not be less than 0.00015 inch (0.0038 mm) thick. Metallic parts are also considered to comply with 6.1 .2.1 when they are protected against atmospheric corrosion by:
a) Hot dipped, mill galvanized sheet steel complying with the coating designation G90 in Table I of the Specification for Sheet Steel, Zinc Coated (Galvanized) or Zinc-Iron-Alloy Coated
(Galvannealed) by the Hot Dip Process, ASTM A653/A653M, or
b) Coatings which have been determined to be equivalent to G90 under the requirements of the Standard for Organic Coatings for Steel Enclosures for Outdoor Use Electrical Equipment, UL 1332.
6.1.2.4 A metallic material other than as described in 6.1.2.1 — 6.1.2.3 shall be painted or protected in a manner that has been determined to be equivalent.
6.2 Nonmetallic materials
6.2.1 General
6.2.1 .1 A nonmetallic part in contact with the fuels anticipated by these requirements, shall be resistant to the action of the fuel if degradation of the material will result in leakage of the fuel, or it it will impair the function of the device.
6.2.1 .2 Gaskets or seals shall comply with the requirements as outlined in Nonmetallic materials — material level, 6.2.2, and Nonmetallic materials — system level, 6.2.3.
6.2.1 .3 Nonmetallic materials in contact with the fuels anticipated by these requirements shall not be constructed of the following:
a) Polysulfide rubber;
b) Ethylene propylene diene monomer (EPDM) rubber;
c) Methyl-Methacrylate;
d) Polyvinyl Chloride (PVC);
e) Nylon 6/6; or
f) Polyurethane.
6.2.2 Nonmetallic materials — material level
6.2.2.1 Seals shall be evaluated in accordance with the Standard for Gaskets and Seals, UL 157, modified as indicated in 6.2.2.2 — 6.2.2.4. If a specific material complies with these requirements, the material can be considered to be qualified for system level testing.
6.2.2.2 A seal shall be constructed of a material that is acceptable in accordance with the scope of the Standard for Gaskets and Seals, UL 157.
6.2.2.3 Seals shall be subjected to the Volume Change and Extraction Test in accordance with the Standard for Gaskets and Seals, UL 157, except for the following modifications:
a) The test duration shall be 1000 hours;
b) The applicable test fluids shall be as described in Supplement SA; and
c) For all materials, the average volume change shall not exceed 40 percent swell (increase in volume) or 1 percent shrinkage (decrease in volume). In addition, the weight loss shall not exceed 10 percent. There shall be no visual evidence of cracking or other degradation as a result of the exposure for any material.