UNE 36-864-1990 Used in distribution networks and gas fuel receiving devices, using longitudinally welded steel pipes with ambient air pressure not exceeding 4 columns (atmospheric pressure)
The tubes will be designated by the following ordered sequence of symbols: a) the letter T (indicative of the type of product); b) the nominal diameter designation (the inch-based number or metric designation may be used interchangeably); Alternatively, the designation based on nominal diameter may be replaced by the average outside diameter followed by the nominal wall thickness, separated by a hyphen; c) the letters N or G, indicative of its non-galvanized or galvanized condition; d) the letters L or R, indicative of its smooth or threaded condition; e) the designation of this standard, with express indication of the date. Example 1: Welded tube with nominal diameter 1/2 (DN 15) galvanized and threaded: Designation: Ti GR UNE 36-864-90 TDN15GR UNE 36-864-90 T 21.3-2.6 UNE 36-864-90 Example 2: Welded tube of nominal diameter 1 (DN 25) black and smooth: Designation: T1 NL UNE 36-864-90 TDN25NL UNE 36-864-90 T 33.7 - 3.2 NL UNE 36-864-90