Tube-To-Tube Sheet Joint Requirements

QW-202.6 Tube-to-Tubesheet Qualification. When the applicable Code Section requires the use of QW-193 for tube-to-tubesheet demonstration mockup qualification tests, QW-193.1 shall apply. f specific qualification test requirements are not specified by the applicable Code Section , tube-to-tube sheet !elds shall be qualified !ith one of the follo!in" methods# (a) "roo$e !elds per the requirements of QW-%&%.% and QW-%&%.' (b) a demonstration mockup per the requirements of QW-193.1 (c) fillet !elds per the requirements of QW-%&%.%(c) (for non pressure retainin" tube-totube sheet !elds only) QW-193 Tube-to-Tube sheet Tests When the applicable Code Section requires the use of this para"raph for tube-totubesheet demonstration mockup qualification, QW-193.1 throu"h QW-193.1.3 shall apply. QW-193.1 Procedure Qualification Specimens. *en mockup !elds are required to qualify each procedure. *he mockup assembly shall essentially duplicate the tube hole confi"uration and the tube-to-tubesheet +oint desi"n !ithin the limits of the essential $ariables of QW-%. *he thickness of the mockup tubesheet is not required to be thicker than % in. (& mm) and the claddin" may be represented by base material of essentially equi$alent chemical composition to the claddin" composition. *he mockup !elds shall be submitted to the follo!in" tests sequentially and must meet the applicable acceptance criteria. QW-193.1.1 cceptance !riteria " #isual $%amination. *he accessible surfaces of the !elds shall be eamined $isually !ith no ma"nification required. *he !elds shall sho! complete fusion and no e$idence of burnin" throu"h the tube !all, and shall be free from crackin" or porosity. QW-193.1.2 cceptance !riteria " &i'uid Penetrant. *he liquid penetrant eamination shall meet the requirements of Section /, 0rticle . *he !eld surfaces shall meet the requirements of QW-19.%. QW-193.1.3 cceptance !riteria " (acro- $%amination. *he mockup !elds shall be sectioned throu"h the center of the tube for macro-eamination. *he four eposed surfaces shall be smoothed and etched !ith a suitable etchant (see QW-'2&) to "i$e a clear definition of the !eld and heat-affected one. 4sin" a ma"nification of 1&5 to %&5, the eposed cross sections of the !eld shall confirm (a) minimum leak path dimension required by the desi"n (b) no crackin" (c) complete fusion of the !eld deposit into the tubesheet and tube !all face (d) complete penetration of the !eld deposit to !ithin 16' in. (&.' mm) of the root of the  +oint (e) porosity shall not reduce the !eld throat belo! the required minimum leak path thickness QW-19) &i'uid Penetrant $%amination QW-19).1 *he liquid penetrant eamination in QW-%1' for corrosion-resistant !eld metal o$erlay shall meet the requirements of Section /, 0rticle . *he acceptance standards of QW-19.% shall be met.

QW-19).2 &i'uid Penetrant cceptance !riteria QW-19).2.1 Terminolo*+ relevant indications # indications !ith ma+or dimensions "reater than 161 in. (1. mm). linear indications # an indication ha$in" a len"th "reater than three times the !idth. rounded indications # an indication of circular or elliptical shape !ith the len"th equal to or less than three times the !idth. QW-19).2.2 cceptance Standards. 7rocedure and performance tests eamined by liquid penetrant techniques shall be +ud"ed unacceptable !hen the eamination ehibits any indication in ecess of the limits specified in the follo!in"# (a) rele$ant linear indications (b) rele$ant rounded indications "reater than 361 in.( mm) (c) four or more rele$ant rounded indications in a line separated by 161 in. (1. mm) or less (ed"e-to-ed"e)