This document describes how to make root weld passes oncircumferential pipe groove welds using open root joints withfiller metal additions, tightly-fitted joints without the additionof filler metal, and joints with consumable inserts. Joint designs,fitting techniques, consumable insert configurations, filler andbase metal combinations, purging, and welding processes arediscussed. This publication does not address joints made usingbacking rings and techniques applicable to mechanized orbitalwelding.
Safety and health issues and concerns are beyond the scope ofthis standard, and therefore are not fully addressed herein. Safetyand health information is available from other sources, including,but not limited to, ANSI Z49.1, Safety in Welding, Cutting, andAllied Processes, and applicable federal and stateregulations. See Clauses 2 and 15 and Annex A for additional safetyand health references.
Introduction.
When the pipe system designer has determined that the use ofbacking rings is unacceptable due to service conditions and thatcomplete joint penetration, including a continuous root sidesurface, is needed, butt joints may be made from one side using thegroove designs and techniques described in this document. Althoughgas tungsten arc welding (GTAW) is most commonly used for precisecontrol in root pass welding, shielded metal arc welding (SMAW) andgas metal arc welding (GMAW) are also widely used.
Units of Measure.
This standard makes use of both the International System ofUnits (SI) and U.S. Customary Units. The latter are shown withinbrackets [ ] or in appropriate columns in tables and figures. Themeasurements may not be exact equivalents; therefore, each systemmust be used independently.
To identify nominal pipe sizes in both SI and U.S. CustomaryUnits, the following designations are used:
1. DN (Diameter Nominal) is the SI designation.
2. NPS (Nominal Pipe Size) is the U.S. Customarydesignation.
- Edition:
- 07
- Published:
- 01/01/2007
- ANSI:
- ANSI Approved
- Number of Pages:
- 36
- File Size:
- 1 file , 580 KB
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