This is a joint Standard with UL 1696. 1 Scope 1.1 This Standard applies to nonmetallic mechanical protection tubing (NMPT) and fittings in 10 to 53 (1/4 to 2) trade sizes for use as support and protection of insulated conductors in equipment intended for use in non-hazardous locations. For tubing and fitting sizes in this Standard, the metric designator is given first, with the trade size in inches following in parentheses. 1.2 Tubing specified by this Standard is intended for use with fittings in compliance with Clause 4.4. The fittings may be for wet or dry locations. 1.3 This Standard does not include tubing used to supply power from the fixed wiring of structures to utilization equipment.