1.1 These requirements cover the 3/8 (12), 1/2 (16), 3/4 (21), 1 (27), 1-1/4 (35), 1-1/2 (41), 2 (53), 2-1/2(63), 3 (78), 3–1/2 (91), and 4 (103) trade sizes (metric designators) of liquid-tight flexible steel conduit.
The conduit covered is intended for installation in accordance with the National Electrical Code (NFPA 70)as raceway for wires and cables in motor circuits operating at potentials over 600 volts, in electric-sign circuits operating at potentials up through 1000 volts, over 1000 volts, and in other circuits operating at 0–600 V.
1.2 This conduit is for applications in which flexibility of the conduit is necessary during installation, operation, or maintenance and the contained conductors need protection from vapors, liquids or solids.
1.3 This conduit is circular in cross section, having an outer liquid-tight, nonmetallic, sunlight-resistant jacket over an inner flexible metal core, and is for use in wet, dry, or oily locations in which the conduit is exposed but is not subject to physical damage. Conduit that is not marked with a temperature designation or is marked "60 C" is for use at temperatures not in excess of 60°C (140°F). Conduit that is for use in dry or oily locations at a temperature higher than 60°C (140°F) is marked "____C dry, 60 C wet, 70 C oil res" or "____C dry, 60 C wet, 70 C oil resistant" with "80 C" or "105 C"inserted as the dry-locations temperature.
1.4 Conduit that is marked "80 C dry, 60 C wet, 60 C oil res" or "80 C dry, 60 C wet, 60 C oil resistant"
is for use at 80°C (176°F) and lower temperatures in air, and 60 °C (140°F) and lower temperatures where exposed to water, oil or coolants - that is, to cutting oils and the like in machine - tool and other industrial applications.
1.5 Conduit marked in accordance with 23.4(g) is limited to use in oil free environments.
1.6 Fittings for liquid-tight flexible steel conduit are covered in the Standard for Fittings for Cable and Conduit, UL 514B.
1.7 These requirements do not cover liquid-tight flexible nonmetallic conduit. Flexible nonmetallic conduit is covered in the Standard for Liquid-Tight Flexible Nonmetallic Conduit, UL 1660, and the fittings for this conduit are covered in the Standard for Fittings for Cable and Conduit, UL 514B.
1.8 These requirements do not cover flexible metallic tubing.
1.9 These requirements do not cover electrical nonmetallic tubing (ENT).