Specifications - City of Montpelier, Vermont

Montpelier District HeatingCity of Montpelier, VTIssue Date:September 28, 2012Title:APPENDIX A – Welding and Testing RequirementsPage #:16 of 223.3.2 Surface Porosity;3.3.3 Excessive weld reinforcement greater than specified in ANSI B31.1,Table 127.4.2;3.3.4 Lack of surface penetration;3.3.5 Incomplete penetration when interior surface is accessible;3.3.6 Undercut shall not exceed 1/32" (0.8 mm) and shall not encroach on theminimum required section thickness;3.3.7 Weld overlap and craters.3.4 Radiography of fabrication welds shall be performed in accordance with thewritten procedure.4.0 ACCEPTANCE STANDARDS4.1 Welds shown by radiography to have any of the following types of discontinuitiesare unacceptable:4.1.1 Any type of crack or zone of incomplete fusion or penetration.4.1.2 Any elongated indication having a length greater than:4.1.2.1 1/4" (6.0 mm) for t up to 3/4" (14.0 mm) inclusive;4.1.2.2 1/3 t for t from 3/4" (19.0 mm) to 2-1/4" (57.0 mm) inclusive;4.1.2.3 3/4" (19.0 mm) for t over 2-1/4" (57.0 mm) where t is thethickness for the thinner portion of the weld.NOTE: "t" referred to in preceding Subparagraphs pertains to thethickness of the weld being examined; if a weld joins two membershaving different thickness at the weld, t is the thinner of the twothicknesses.4.1.3 Any group of indications in line with an aggregate length greater than t ina length of 12t, except where the distance between the successiveindications exceeds 6L, where L is the longest indication in the group.4.1.4 Porosity in excess of that shown as acceptable in App A-250 of Sec I ofthe ASME Boiler and Pressure Vessel Code.5.0 RE8EXAMINATION OF REPAIRS5.1 Repairs of all defects disclosed by radiography shall be reexamined inaccordance with this Specification.6.0 FREQUENCY OF FIELD RADIOGRAPHIC EXAMINATIONRadiographic inspection shall be performed according to the following schedule:6.1 The ENGINEER will perform a minimum of ten (10) percent of the total butt weldsperformed by each welder.6.2 If defects are detected in the work of a welder, the inspection of the work done bythat welder shall be expanded at CONTRACTOR expense, to comprise a total ofat least three additional joints; however, the additional radiography shall includenot less than 6' of weld. These tracers may be taken anywhere on the Projectwhere there are exposed and accessible welds previously made by the welder.6.3 If any joint in the expanded inspection is rejected, further radiography shall beconducted to provide 100 percent coverage of work previously done by thatAPPENDIX APage A16