UL 92-2020 pdf download

UL 92-2020 pdf download.Fire Extinguisher, Booster, and Noncollapsible Standpipe Hose and Hose Assemblies.
4.2 Thicknesses 4.2.1 The thickness of a tube shall not be less than 0.060 inch (1.52 mm), and that of a cover not less than 0.047 inch (1.19 mm), when determined in accordance with 4.2.2 – 4.2.5. 4.2.2 For buffing off irregularities in the sample, the buffing machine specified in the Recommended Practice for Rubber-Preparation of Pieces for Test Purposes from Products, ASTM D3183-84 (1992), is to be used. The dial micrometer specified in the Test Methods for Rubber Properties in Tension, ASTM D412- 92, is to be used for measuring thickness. 4.2.3 One piece, approximately 6 – 8 inches (152 – 203 mm) long, taken from the sample selected for physical and detail tests, is to be used in determining the thickness of the lining and cover in accordance with 4.2.4 and 4.2.5. 4.2.4 A strip, approximately 6 – 8 inches (152 – 203 mm) long and 1 inch (25 mm) wide, or as close to 1 inch wide as possible from small diameter hose, is to be cut from the hose, and the rubber part separated from the plies. If the thickness of the part is not uniform around the circumference of the hose, the strip is to be cut from the thinnest portion of the sample. 4.2.5 The strip sample is to be buffed just sufficiently to remove the impressions left by the fabric or braid or other surface irregularities, using the buffing machine described in 4.2.2. A series of five thickness measurements is to be taken within the area from which the impressions have been removed, and the maximum reading obtained is to be taken as the thickness of the rubber part.
5 Reinforcement 5.1 Wrapped Type 5.1.1 Wrapped-type hose sized 5/8 inch (15.9 mm) or smaller shall have at least three plies of fabric. Hose sized larger than 5/8 inch shall have at least four plies of fabric. 5.2 Braided and Spiraled Type 5.2.1 Plies of reinforcement shall be of cotton or synthetic fibers, or corrosion resistant material such as stainless steel and shall be evenly and firmly applied over the tube. Braids and spirals shall be thoroughly impregnated with a rubber compound that shall cause the plies to adhere firmly to each other and to the rubber tube and cover. 5.2.2 Hose in 3/8 and 7/16 inch (9.5 and 11.1 mm) sizes shall have at least one braid or two plies of spirals. Hose in sizes larger than 7/16 inch and up to 5/8 inch (15.9 mm) shall have at least two braids or four plies of spirals. Hose larger than 5/8 inch shall have at least three braids or six plies of spirals. 5.2.3 Adjacent plies of spirals shall be wound in opposite directions. Hose having a lesser number of braids or spirals than specified in 5.2.2 may be considered acceptable if found by investigation to (1) comply with the other requirements in this standard, and (2) be equivalent with respect to kink resistance and deformation resistance to hose having the specified number of braids or spirals.
7 Couplings 7.1 A hose coupling shall be made of corrosion resistant material. See Salt Spray Corrosion Test, Section 22. PERFORMANCE 8 Elongation and Contraction Test 8.1 General 8.1.1 The change in length of the hose or hose assembly, when pressurized from 10 psig (69 kPa) to the maximum working pressure, shall be plus 4 to minus 6 percent for sizes less than 3/4 inch (19.1 mm) and plus 6 to minus 0 percent for sizes 3/4 inch and larger. 8.2 Apparatus 8.2.1 The hydrostatic equipment specified in Methods of Testing Rubber Hose, ASTM D380-94, is to be used for this test. 8.2.2 The necessary equipment and facilities are to include a test surface or the equivalent that will provide a clear space at least 20 inches (508 mm) wide on each side of a line drawn through the center of the supply connection and parallel to the edges of the test surface.UL 92-2020 pdf download.