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1、Nr. VEP 003 rev. 0Page 1 of 9 June 06, 2021STILMAS VISUAL EXAMINATION PROCEDUREINDEX1. SCOPE22. APPLICABILITY 22.1 TEST OBJECT22.2 STAGE OF EXAMINATION22.3 EXTENT OF EXAMINATION23. APPLICABLE DOCUMENTS24. GLOSSARY 35. PERSONNEL35.1 RESPONSIBILITY 35.2 QUALIFICATIONS 36. CALIBRATIONS 37. SURFACE COND
2、ITIONS37.1 WELDS37.1.1 Clea nli ness and end preparati on before weldi ng37.1.2 Weld surfaces after back goug ing 47.1.3 Fini shed weld surfaces47.2 BASE MATERIALS47.2.1 Edge fin ish48. TESTING EQUIPMENTS AND TECHNIQUE49. REPORTING LEVELS AND EVALUATION410. ACCEPTANCE CRITERIA410.1 WELD JOINT PREPAR
3、ATION410.1.1 Bevels for groove welds410.1.2 Fit-up and in ter nal alig nment510.1.3 Gap for fillet welds 610.2 BUTT WELD SURFACE AFTER BACK GOUGING610.3 ACCEPTANCE LIMITS IN FINISHED WELD SURFACE610.3.1 Gen eral requireme nts610.3.2 Excess of depth610.3.3 Excess of appare nt dime nsions 610.3.4 Exce
4、ss of rein forceme nt or un derfill 610.4 BASE METAL SURFACE AND ROLLED PRODUCT FORMS CUT EDGES810.4.1 Plate or pipe or pipe fitt ings 810.4.2 Forgings910.5 CUT EDGES OF ROLLED PRODUCT FORMS 911. MARKING912. REPORTING90June 2021P. Bere nganR.Pa nizzaRev.DatePreparedApprovedAI AcceptedNr. VEP 003 rev
5、. 0Page 2 of 9 June 06, 2021危 STILMAS VISUAL EXAMINATION PROCEDURE1. SCOPEThis procedure fur ni shes in structi ons to exam in ers and in spectors for the performa nee of satisfactory VE of:? welds and their adjace nt pare nt metal;? base metals of welded or non welded parts;? cut edges to be welded
6、.2. APPLICABILITY2.1 TEST OBJECTThis procedure covers pressure pip ing, pressure vessels and parts of pressure vessels( except exter nal pressure pip ing) desig ned, fabricated and tested in accorda nee with Con structi on Code ASME Sect. VIII Div.1.This procedure is applied to C steel, low alloy st
7、eel, high alloy steel and cladded steels, excluded que nched and tempered steels.2.2 STAGE OF EXAMINATIONWhen specifically required by releva nt fabricati on and quality con trol pla n, the VE refere need here in shall be made at any stage required by Customer Specificati ons and, as mini mum, at fo
8、llow ing stages:a) WELD JOINT PREPARATION OF BUTT WELDS? VE of bevels.? VE of fit-up and internal alignment prior to welding.b) WELD SURFACE AFTER BACK GOUGING? VE of weld surface soundness after back-gouging (for joints welded from both sides).c) FINISHED WELD? VE of weld surface soundness.d) BASE
9、METAL SURFACE? Before start ing of fabricati on, and duri ng and after fabricati on, VE of surface for defects due to fabricati on errors or in correct han dli ng and for defects detected on parts surfaces cut, mach in ed, formed, etc. dur ing fabricati on.e) CUT EDGES OF ROLLED PRODUCT FORMS? VE of
10、 cut edges before welding. Where delayed cracking may occur in thermally cut material, edges shall be inspected not immediately after the cutting, but at a more appropriate stage (e.g. after bevelling or after fitting-up).2.3 EXTENT OF EXAMINATIONa) 100 % of:? finished welds;? all base metal surface
11、s;? cut edges of rolled product forms.b) in-process monitoring of:? weld joint preparation of butt welds;? weld surfaces after back gouging.3. APPLICABLE DOCUMENTSThis procedure is referred to the follow ing docume nts (in editi ons and adde nda applicable at date of this revisi on of procedure):? E
12、mployer Quality Con trol Man ual, latest revisio n.? Standard Specifications of main Customers.? ASME Sect. VIII Div.1 UG-16, UG-79, UG-90, UG-93, UG-95, UG-97, UW-31 to UW-39 and other applicable paragraphs.Nr. VEP 003 rev. 0Page 3 of 9 June 06, 2021危 STILMAS VISUAL EXAMINATION PROCEDURE4. GLOSSARY
13、Flaw = an imperfecti on or uninten ti onal disc；on tin uity which is detectable by VE (visual exam in ati on) an d/or NDE (non destructive exam in ati on).Defect = a flaw of such size shape, orientation, location or properties as to be rejectable against accepta nee criteria of Customer Specificati
14、ons an d/or Con structi on Code.VE = visual exam in ati on of the surface portions that are or can be exposed to view before, duri ng or after fabrication operations.NDE = non destructive exam in ati on.Exam in ati on = quality con trol fun cti ons performed by pers onnel employed to the man ufactur
15、er.Exam in ati on deno tes the practices for visual observati on.In specti on = quality con trol fun cti ons performed by Shop Super intent un der the guida nee and supervisi on of QC In spector or performed by QC in spector. I nspecti on deno tes verify ing the performa nee of above exam in ati on.
16、5. PERSONNEL5.1 RESPONSIBILITYExam iner visually exam ines the preparati on of the joi nt.Exam iner visually exam ines the weld.Quality Con trol In spector is resp on sible for:? pla nning the exam in ati ons before fabricati on start ing on the quality con trol pla n or equivale nt docume nt;? revi
17、ewi ng, fili ng and mai ntai ning the VE (visual exam in ati on) records.Shop Superi ntendent and Weld ing Coord in ator is resp on sible for timely in terve nti on of Quality Con trol In spector.5.2 QUALIFICATIONSExam iner performi ng visual exam in ati ons shall have trai ning and experie nee comm
18、e nsurate with the n eeds of the specific exam in ati on.6. CALIBRATIONSCalibration of groove and fillet welds gauges shall follow the general calibration procedure.7. SURFACE CONDITIONSThe surface should be illuminated, if necessary with flashlight or other auxiliary lighting, to attain a mi ni mum
19、 of 15 foot-ca ndles (=160 lx) for gen eral exam in ati on and a mini mum of 50 foot-ca ndles (=540 lx) for the detecti on or study of small ano malies.7.1 WELDS7.1.1 Clea nli ness and end preparati on before weld ingWeldi ng surfaces and adjace nt adjoining surfaces for a dista nee of at least 12.7
20、 mm shall appear throughly clea ned of loose rust, mill scale, foundry scale, accumulati ons of slag or bur nt metal, oil, grease, paint, dirt, moisture, protective coatings or other materials which may detrimentally affect the weld or the base metal.The surface of butt weld end preparati on shall a
21、ppear reas on ably smooth and true and all slag from oxyge n or arc cutt ing, scale and severe no tches shall have bee n clea ned from flame cut surfaces. Discoloration which remains on a flame cut surface in P1, P3, P7 or P11A Gr.1 ASME P-No.s steel is not considered to be detrimental oxidation.Pla
22、 in edges in plates more tha n 10 mm thick, if cold sheared, shall have bee n dressed back mecha ni cally to provide a suitable surface to permit a satisfactory VE of the edges prior to weldi ng.Nr. VEP 003 rev. 0Page 4 of 9 June 06, 2021危 STILMAS VISUAL EXAMINATION PROCEDURE7.1.2 Weld surfaces afte
23、r back gougi ngThe sec ond side of jo ints welded from both sides shall appear free from slag and clea ned back to sou nd metal before deposit ing weld metal at the sec ond side, unl ess the qualified WPS has dem on strated that satisfactory fusi on and pen etrati on are obta in ed.7.1.3 Fini shed w
24、eld surfacesThe surface of the fini shed weld shall satisfy the follow ing:a) Grooves for butt welds shall be completely filled and built up on each side with additional weld metal. Where the additi onal metal exceeds the maximum acceptable limits, it shall be removed to provide a smooth con tour. S
25、urfaces of butt and corner welds required, by Customer Specificati ons, to be flush shall be fini shed so as not to reduce the thick ness of the thinner base metal or weld metal by more tha n the smaller value of 0.25 mm or 6% of the thick ness.b) The surface of the weld along and across the joint s
26、hall be reas on ably smooth and free from sharp irregularities, grooves or depressions, and shall merge smoothly into the plate surface.c) There the weld is grou nd or machi ned flush, care shall have bee n take n to avoid un derflush ing, overheating of the joint and the introduction of grinding cr
27、acks.7.2 BASE MATERIALSAll materials shall have a workmanlike finish. All surfaces shall be sufficiently clean to permit adequate exam in ati on.7.2.1 Edge fin ishEdges of shell and reinforcing plates which will not be fused by welds shall be reas on ably smooth and free from severe gouges, grooves,
28、 or no tches no rmal to the plate surface.Unless otherwise permitted by applicable Fig. of the Construction Code, the arris of exposed ends ofbra nches or man hole which have to rema in un welded in the completed vessel shall have bee n chamfered to 45 °o at least 0,3 mm, whichever is less, whe
29、 n the inner end of the no zzle n eck is flush with the in side wall of the shell. When the inner end of the no zzle n eck protrudes bey ond the in side wall of the shell toward the cen ter of curvature, the exposed in side edges shall be chamfered to 45to least 0,°mm onboth inner and outer sur
30、faces of the n eck end.8. TESTING EQUIPMENTS AND TECHNIQUEDirect visual exam in ati on shall be made whe n access is sufficie nt to place the eye within 610 mm of the surface to be exam ined and at an an gle not less tha n 30to the° surface to be exam in ed. Mirrors may beused to improve the an
31、 gle of visi on, and aids such magnifying lens ( up to 10x) may be used to assist exam in ati on. Groove and fillet gauges have to be used for dime nsional check of size of welds. Where access for exam in ati on is not practicable or not easy, en doscope may used to aid exam in ati on.9. REPORTING L
32、EVELS AND EVALUATIONOnly flaws exceeding acceptance criteria need to be recorded in a test report.10. ACCEPTANCE CRITERIA10.1 WELD JOINT PREPARATION10.1.1 Bevels for groove weldsBevel angle tolerance shall be2,5 ° unless otherwise indicated in the WPS or the joint detail drawing.Root face shall
33、 be +-0.8 mm of tolerance, unless otherwise indicated in the WPS or in the joint detail draw ing.Surfaces to be welded shall be smooth and free from no tches or sudde n cha nges of shape, or defects which could be the cause of weld defects.Nr. VEP 003 rev. 0Page 5 of 9 June 06, 2021STILMAS VISUAL EX
34、AMINATION PROCEDURE10.1.2 Fit-up and internal alig nmentThe shape of the weld preparation shall also agree with that given in the qualified WPS and in the weld detail draw ing, so that en able the required pen etrati on and completed fusi on of the whole of the fusi on faces to be obta in ed.Adjace
35、nt comp onents which have to be welded shall be assembled, alig ned and reta ined in positi on for weldi ng to en sure that the root gap and alig nment are maintained duri ng weld ing and that the required shape of the assembly is obta ined for weld ing.For butt joi nts of adjace nt base metals of u
36、n equal thick nesses, any offset within the allowable tolera nee shall be faired to 3/1 taper over the width of the fini shed weld.Before attachi ng no zzles, man hole frames, no zzle rei nforceme nt and other appurte nan ces to the in side or outside of the vessel, they shall be checked to properly
37、 fit the vessel curvature.After fitting-up, the tolerance on the groove angle, if not otherwise specified on the drawing or on theWPS, after fitting-up, is to be intended5°. The tolerance on the gap, if not otherwise specified on thedraw ing or on the WPS, after fitt in g-up, is to be inten ded
38、1 mm.TABLE UW-33Customary Un itsMaximum Misalig nmentJoint CategoriesSecti on Thick ness, in.AB, C, & DUp to ?, i ncl.? t? tOver ? to ?, i ncl.1/8 in? tOver ? to 1?, i ncl.1/8 in3/16 inOver 1? to 2, i ncl.1/8 in1/8 tOver 2Lesser of /16 t or /8 inLesser of /8 t or /4 inSI UnitsMaximum Misalig nme
39、ntJoint CategoriesSecti on Thick ness, mmAB, C, & DUp to 13, i ncl.? t? tOver 13 to 19, i ncl.3 mm? tOver 19 to 38, i ncl.3 mm5 mmOver 38 to 51, i ncl.3 mm1/8 tOver 51Lesser of /16 t or 10 mmLesser of /8 t or 19 mm10.1.2.1 Tack weldsTack welds which rema in in place shall be fused with the root
40、pass weld, except that those which have cracked or have bee n affected by defects shall be removed. Bridge tacks (above the root) shall be removed.The un welded or tack welded lon gitud inal joints of rolled courses shall not show flat spots caused by improper rolli ng.10.1.2.2 Backing strips and co
41、nsumable insertsBack ing strip or ring material and type, and con sumable in serts (if used) shall be con form to the qualified WPS.A backing strip or ring, where used, shall be a close fit to the plates being welded.Nr. VEP 003 rev. 0Page 6 of 9 June 06, 2021危 STILMAS VISUAL EXAMINATION PROCEDURE10
42、.1.3 Gap for fillet weldsNozzles subjected to pressure, ope nings rein fore ing pads and attachme nts carry ing exter nal loads, which have to be fillet welded, shall fit closely to the shape of the surface to which they are attached and kept together duri ng weld ing (See Fig. A).10.2 BUTT WELD SUR
43、FACE AFTER BACK GOUGINGSurfaces to be welded shall be smooth and free from notches, sudden changes of shape, irregularities and disc on ti nuities which could be the cause of weld defects.10.3 ACCEPTANCE LIMITS IN FINISHED WELD SURFACE10.3.1 Gen eral requireme ntsAll welds shall be visually examined
44、 to ensure that the surface is free of coarse ripples, grooves, overlaps, abrupt ridges or valleys, and flaws exceeding acceptance limits.Defin ition of thick ness (see ASME VIII Div.1UGW-§0(f):? for groove butt welds, the depth of the groove in dicated in the draw ing (for butt welds of adjace
45、 nt pare nt metals of un equal thick nesses, con sider the draw ing thick ness of the thi nner adjace nt part);? for fillet cor ner weld, the mini mum desig n throat dime nsion;? for groove corner weld, where a fillet weld is used in conjunction with a groove weld, the greater of above.Follow ing fl
46、aws are con sidered defects:10.3.2 Excess of depthAny visually detected surface defect where the reducti on in thick ness may be evaluated to exceed 0.8 mm or 10% (whichever is less) of the thick ness, such as:? un dercuts;? elon gated (le ngth greater tha n 3 times the width) in dicati ons;? roun d
47、ed (le ngth equal or less tha n 3 times the width) in dicati ons.10.3.3 Excess of appare nt dime nsions? Cracks.? Elo ngated in dicatio ns over the limits ofUW-51(b)(2).? Roun ded in dicati ons over the limits of Appe ndix 4 of the Con structi on Code.? Roun ded in dicati on greater tha n 4,8 mm.? F
48、our or more roun ded in dicati ons in a line separated by 1,6 mm or less edge to edge.10.3.4 Excess of rein forceme nt or un derfillFollowing imperfections detected visually with aid of butt weld/fillet weld size gauges: ? Arc bur ns.? For butt welds, thick ness of weld rei nforceme nt on each face exceedi ng the followi ng:Nr. VEP 003 rev. 0Page 7 of