UL 330-2021 pdf free download.Hose and Hose Assemblies for Dispensing Flammable and Combustible Liquids.
4 TubeandCover
4.1 Single-line hose and double-line vapor recovery hose
4.1.1 The tube shall be made from a material resistant to gasoline and diesel fuel.
4.1.2 The cover shall be made from a material resistant to gasoline, diesel fuel, oils, and ozone.
4.1.3 The tube and cover shall be of uniform thickness, and free from pitting, blisters, or other imperfections. This requirement is not intended to exclude the use of a corrugated cover.
NOTE: This Standard provides requirements for both coazia vapor recovery hose types where the bqu.d is conveyed through the inner hose and the vapor is recovered from the outer hose, as well as. vice versa.
4.2 Coaxial vapor recovery hose
4.2.1 The tube and cover, if any, of the inner hose shall be made from materials resistant to gasoline and diesel fuel.
4.2.2 The tube of the outer hose or a homogeneous outer hose shall be made from materials resistant to gasoline and diesel fuel.
4.2.3 The cover of the outer hose or a homogeneous outer hose shall be made from a material resistant to gasoline, diesel fuel, oil, and ozone.
4.2.4 The tube and cover shall be of uniform thickness and free from pitting, blisters, or other imperfections. This requirement is not intended to exclude the use of a corrugated tube, cover, or outer vapor recovery hose.
5 Thickness of Cover
5.1 The thickness of the cover shall not be less than 0.047 in (1.19 mm) when measured in accordance with 5.2 — 5.6.
Exception: This requirement does not apply to the cover of the inner hose and the outer vapor conveying hose of a coaxial vapor recovery hose.
5.2 For removing irregularities in samples, the buffing machine or skiving machine outlined in the Standard Practice for Rubber — Preparation of Product Pieces for Test Purposes from Products, ASTM 03183, shall be used.
5.3 The abrasive wheel of the buffing machine shalt be No. 30 — 60 grit and the diameter and rotary velocity of the wheel shall be such that it will have a peripheral speed of 4000 ±700 ft/mm (20.3 ±3.6 mIs). The machine shall be provided with a slow feed so that very little compound can be removed at one cut to avoid overheating of the specimen.
5.4 A dial micrometer graduated to 0.001 in (0.03 mm) that exerts a load of 2.82 — 3.00 oz (80—85 g) by means of a weight shall be used to measure thickness. The load shall be applied through a flat contact foot 0.25 ±0.01 in (6.4 ±0.3 mm) in diameter.UL 330 pdf download.