1、 PFI Standard ES-35 (Reaffirmed September 2003) NONSYMMETRICAL BEVELS AND JOINT CONFIGURATIONS FOR BUTT WELDS METRIC CONVERSIONS The conversion of quantities between systems of units involves a determination of the number of significant digits to be retained. All conversions depend upon the intended
2、 precision of the original quantity and are rounded to the appropriate accuracy. Pipe sizes together with applicable wall thickness are not shown with metric equivalents. The SI (Metric) values where included with the customary U.S. values in this Standard are the rounded equivalents of the US value
3、s and are for reference only. Metric units were derived utilizing the following conversion factor: Conversion Factor inches to millimeter 25.41. Scope 1.1 This Standard covers the end preparation of non-symmetrical bevels and joint configurations for butt welds in piping systems. 2. Joint Design 2.1
4、 In establishing a joint design, the basic aim is to assure accessibility of the welding electrode in the joint so that full penetration in the weld may be achieved. Restricted access results in failure to achieve full penetration and leaves unjoined surfaces. Access greater than that required to ac
5、hieve full penetration requires more filler metal and creates higher costs because more consumables and labor are required to deposit the extra filler metal. 3. Joint Configuration 3.1 Piping components, such as fittings and flanges, are normally furnished with a mill bevel of 37 degrees in wall thi
6、ckness of 7/8” (22mm) or less (See Fig. 1) and a compound bevel of 37 10 degrees in wall thickness greater than 7/8” (22mm) (See Fig. 2). However, beveled pipe from the mill is usually furnished with a 30-degree bevel. 3.2 The end preparation as shown in the WPS is considered to be a non-essential v
7、ariable by the ASME Boiler and Pressure Vessel Code, Section IX. Therefore, dimensions shown in Figures 1, 2 and 3 may be modified to suit the joint configuration and the selected welding process. The adjacent weld bevels need not be symmetrical about the joint centerline. 4. General Comments 4.1 Th
8、is Standard is intended to primarily cover the following welding processes, used individually or in combination: GMAW Gas Metal Arc Welding (M.I.G.) FCAW Flux Core Arc Welding SMAW Shielded Metal Arc Welding (Stick Rod) SAW Submerged Arc Welding GTAW Gas Tungsten Arc Welding (T.I.G.) 4.2 For additio
9、nal information on joints utilizing solid machined backing rings, refer to PFI Standard ES-1. 4.3 For additional information on joints prepared for GTAW of the root pass, refer to PFI Standard ES-21. 4.4 Asymmetric joints shown in this standard may be used in conjunction with PFI Standards ES-1 and
10、ES-21. 3/4“(19 mm)Nom.55 to 803/16“ Nominal(4.5 mm)FIG. 37/8“(22mm)Nomimal3/32“Max.(2.5mm)3/32“Max.(2.5mm)45 to 6055 to 803/32“Max.(2.5mm)3/4“(19 mm)Nom.3/16“ Nominal(4.5 mm)FIG. 23/16“ Nominal(4.5 mm)FIG. 11010103/4“Nom.(19mm)201. A flat split backing ring may be used if the Welding Procedure permits2. For some Welding Processes the root face may be feather edgeNotesPFI Standard ES-35 (Reaffirmed September 2003)
