ACCEPTANCE CRITERIA OF WELD DEFECTS AS PER DIFFERENT CODES Dr G RavichandranSr Manager, WRIBHEL, Tiruchirappalli

ASTM B 31.1 BOILER PIPING CODE VISUAL EXAMINATION Acceptance criteria

Cracks on external surfaceUndercuts on external surface > 1 mm deepWeld reinforcement more than specifiedLack of fusion on surfaceIncomplete penetration in root if accessible

MAGNETIC PARTICLE EXAMINATION Relevant indication is one from unacceptable mechanical discontinuities. Size of indication is the criteria and not the size of defect. Acceptance criteriaCracks or linear indication ( L > 3 W)Rounded indications dimension > 4.8 mmFour or more rounded indications in a line separated by 1.6 mm edge to edgeTen or more rounded indications in any 6 sq. in. surface with major dimension < 6 in. ASTM B 31.1 BOILER PIPING CODE

ASTM B 31.1 and ASME VIII RADIOGRAPHIC EXAMINATION Acceptance criteriaCracks or incomplete fusionElongated indications 6.4 mm for thickness up to 19 mm1/3 t for thickness from 19 - 56 mm19 mm for thickness more than 56 mmGroup of aligned indications with aggregate length more than t in a length of 12 tRounded indications as per chart

ASME VIII BOILER & PR VESSEL CODE ROUNDED INDICATIONS A sequence of 4 or more rounded indications are aligned when they touch a line parallel to length of line drawn through center of outer indications

thicknessRelevant indication1/8 t / 101/8 to 1/41/641/4 to 21/32> 21/16

ASME B 31.3 PROCESS PIPING CODE - NON DESTRUCTIVE EXAMINATION REQUIRED Visual examination of randomly selected materials Visual examination of 5% min of fabrication 100% visual examination of longitudinal welds Random visual examination during erection of piping for defects which require repair Minimum 5% of circumferential butt welds shall be examined by random RT. For cyclic loaded pipe, 100% RT needed When circ. joint intersects with long. joint at least 38 mm of each intersecting weld shall be examined

Acceptance Criteria as per ASME B 31.3Normal fluid service(a) Crack, Lack of fusion (VT &RT) No evident imperfection(b) Incomplete penetration (VT & RT) in Long grooves no evident imperfection. In girth welds and branch conn., depth permitted is 1 mm and 0.2 t. Cumulative

Acceptance Criteria as per ASME B 31.3Normal fluid service(f) Surface porosity (VT) No evident imperfection(g) Concave root surface in butt welds (VT & RT) - Total joint thickness incl weld reinf > t(h)Reinforcement or internal protrusion (VT)t Max height255

Acceptance Criteria as per ASME B 31.3Severe cyclic condition(a) Crack (VT,RT,MT,PT), Lack of fusion (VT,RT) - No evident imperfection(b) Incomplete penetration (VT & RT) in girth, long and branch welds no evident imperfection. (c) Internal porosity (RT) in girth, long, branch con., as per ASME VIII(d) Slag / W inclusion (RT) in girth, long and branch welds - individual length < t/3, individual width < 2.5 mm & t/3, cumulative length < t in any 12 t weld length

Acceptance Criteria as per ASME B 31.3Severe cyclic condition(e)Undercut, surface porosity or exposed slag (VT) - no evident imperfection(f) Surface finish (VT) less than 500 Ra (g) Concave root surface in butt welds (VT & RT) - Total joint thickness incl weld reinf > t(h)Reinforcement or internal protrusion (VT)t Max height255

Acceptance Criteria as per ASME B 31.3Category D fluid service(a) Crack (VT) - No evident imperfection(b)Lack of fusion (VT) in long & branch weld - No evident imperfection. In girth weld, depth < 0.2 t cumulative length < 38 mm in any 150 mm length(c) Incomplete penetration (VT ) in girth weld same as lack of fusion. In long weld no evident imperfection. In branch welds depth < 1 mm & 0.2 t. Cumulative length < 38 mm in any 150 mm length (d) Undercut (VT) in girth weld < 1.5 mm & < t/4. In long weld no evident imperfection. In fillet and branch weld < 1 mm & t/4(e) Surface porosity (VT) no evident imperfection

Acceptance Criteria as per ASME B 31.3Category D fluid service(f)Concave root surface in butt welds (VT) - Total joint thickness incl weld reinf > t(g)Reinforcement or internal protrusion (VT)t Max height2510

AWS D 1.1 STRUCTURAL WELDING CODEStatic load, Cyclic load & Tubular connections

(a) CrackWeld shall have no crack(b) Weld / Base Thorough fusion shall exist bet WM/BM metal fusionand adjacent layers of WM(c )Crater Crater to be filled to full cross section except for stitch welds outside eff. Len.(d) Weld profileIn conformance with sketch(e)Inspection VT to start after weld cools to room temp(f) UnderrunUnderrun in fillet weld nominal size 1.6 mm provided it is < 10% length. In Web to flange welds, it is not permitted

AWS D 1.1 STRUCTURAL WELDING CODE

(g) Undercut In static loading, 1 mm permitted for t25mm. For t

AWS D 1.1 STRUCTURAL WELDING CODEPorosityIn static loading, for other grooves and fillets sum of porosity with dia > 1mm, should be < 10 mm in any linear inch of weld and < 19 mm in any 305 mm weldFor cyclic loading and tubular connection, the frequency of piping porosity in other cases should be < one in 100 mm weld length and max dia < 2 mm. In cyclic loading and tubular connections, for fillet welds connecting stiffeners to web, the sum of dia of piping porosity

AWS D 1.1 STRUCTURAL WELDING CODEMax clearance between edges c in mm, c=3b=2eWeld size orthroate, mm19 mm maxb- max size of elongated discontinuities3229 or more57

AWS D 1.1 STRUCTURAL WELDING CODERADIOGRAPHY FOR STATICALLY LOADED STRUCTUREElongated indication and spacing as per chartRounded indications > E/3 not to exceed 6 mm (except for t>2 it is 10 mm) and gap should be > 3 LIsolated discontinuities like clusters with sum of dimensions not to exceed chart and gap < 3 L Sum of individual discontinuities each having max dimension < 2 mm, shall not exceed 2 E /3 (10 mm max) in any linear inch of weld. In line discontinuities with sum of greatest dimension < E in any 6E length of weld