ASME射线规程

HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 1 of 20 CONTENTS 1 General 2 Qualification of examination personnel 3 Equipment tools and materials 4 Check of surface to be radiographed 5 Examination 6 Film processing 7 Evaluation of radiographs 8 Nonconformity control 9 Records and archiving HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 2 of 20 1 GENERAL 1 1This procedure provides the X ray radiographic examination technique for butt welds of pressure vessels constructed in accordance with the requirements of the ASME Code Section Div 1 1 2This procedure shall be supplemented with the examination instructions defining more specific variables which will be approved by NDE level III Examiner 2QUALIFICATION OF EXAMINATION PERSONNEL 2 1Any person engaged in this examination shall be qualified as radiographic examiner in Accordance with the requirements of HT s Written Practice for NDE Personnel Training Examination Qualification and Certification No HT0501 99 which is based on the requirements of SNT TC IA current code accepted edition 2 2The NDE level I shall receive the necessary instruction or supervision from a certified NDE level II or level III examiner The NDE level II shall receive the instruction or supervision from a NDE level III examiner 2 3According to the respective responsibility range all examiners shall complete the examination conforming to the ASME Code this procedure and the written instructions They shall assure the working quality 3 EQUIPMENT TOOLS AND MATERIALS Level II examiner shall select the equipment tools and materials and assure they are in compliance with The following conditions and the requirements of the examination instruction 3 1 One of the X ray equipment listed in Table 1 shall be used Table 1 ModelFactory Max Tube Voltage Max Tube Current Effect Focal Size mm Material Thick mm 300 EG B2LF JIS 300 kV5 mA2 3 2 360 mm XXH 3005Dan Dong300KV5 mA1 0 2 546 mm XXQ 3005Dan dong300KV 5mA1 0 2 5 50mm HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 3 of 20 3 2 Film 3 2 1 Film selection shall be in accordance with SE 1815 standard Test Method for Film Systems for Industrial Radiography The film manufacturer shall determine the film system class for the family of films manufactured and provide a classification table Film system classes Special W A and W B are Permitted 3 3 Screen The following thickness of lead Pb screen shall be used Table 3 Energy of RadiationThickness of Screen mm FrontBack 120 kvp0 01 0 10 120 250 kvp0 025 0 16 0 10 250 420 kvp0 05 0 16 0 10 3 4 Densitometer and Step Wedge Comparison Film The densitometer listed inTable4 shall be used for judging radiograph density The densitometer shall be calibrated in accordance with SE1079 Standard proctice for calibration of Transmission Densitometers using a calibrated step Wedge Film traceable to a National standard Calibration record of transmission Densitometer see Exhibit 15 Table 4 Brand ManufacturerMeasurement Range TD 210 Ou Hai Zhejiang0 4 0 3 5 Penetrameter 3 5 1The ASME standard wire type Penetrameters shall be used in the radiographic examination the form of the wire type Penetrameter see the fig 1 HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 4 of 20 WIRE PENETRAMETER SIZES Wire Diameter in mm A type B type C type D type 0 0032 0 08 0 004 0 1 0 005 0 13 0 0063 0 16 0 008 0 2 0 010 0 25 0 010 0 25 0 013 0 33 0 016 0 4 0 020 0 51 0 025 0 64 0 032 0 81 0 032 0 81 0 040 1 02 0 050 1 27 0 063 1 6 0 080 2 03 0 10 2 5 0 10 2 5 0 126 3 2 0 160 4 06 0 20 5 1 0 25 6 4 0 32 8 0 Fig 1 Form of Wire Type Penetrameter The 0 0032 wire may be used to establish a special quality level as agreed Upon between the purchaser and the supplier 3 5 2For all carbon steels all low alloy steels and all stainless steels the materials group 1 IQI made of carbon steel or TYPE 300 series stainless steel shall be used For the other materials suitable IQI shall be selected in accordance wire the materials group specified in SE 1025 3 5 3 The designated pentameter shall be selected from Fig 1 and table 5 according to the thickness and material to be examined 3 5 4Placement of Penetrameter HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 5 of 20 3 5 4 1 The penetrameter shall be placed on the source side of the part being examined except when hand placing is prevented by the construction of the part the film side penetrameter when used shall be placed on the film side in contact with the part being examined The letter F shall be placed adjacent to or on the penetrameter but shall not be in the area of interest The lead letter F has the seam dimension as the penetrameter identification numbers The letter F is placed as shown in Fig 3 3 5 5For given product the penetrameter designation and quantity shall be defined in the Examination instruction 3 5 6The number of penetrameters shall be so determined that a minimum of one penetrameter Covers the area where the density of radiograph does not vary by more than minus 15 Or plus 30 from the density through that penetrameter body Additional penetrameters Shall be used for areas out of the allowable density range described above 3 6 B Mark Following size of a lead B shall be attached to the back of the film holder for checking the back scattered radiation Fig 2 8mm 13mm B 1 6mm Fig 2 B Mark HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 6 of 20 Table 5 Selection of IQI Nominal Single Wall Material Thickness Range in mm Source SideFilm Side Hole type Designation Essential Hole Wire diameter in mm Hole type Designation Essential Hole Wire diameter in mm up to 0 25 6 35 incl 12 2T0 008 0 20 10 2T0 006 0 15 Over 0 25 6 35 through 0 375 9 5 15 2T0 010 0 25 12 2T0 008 0 20 Over 0 375 9 5 through 0 50 12 7 17 2T0 013 0 28 15 2T0 010 0 25 over 0 50 12 7 through 0 75 19 05 20 2T0 016 0 38 17 2T0 013 0 28 over 0 75 19 05 through 1 00 25 4 25 2T0 020 0 51 20 2T0 016 0 38 Over 1 00 25 4 through 1 50 38 10 30 2T0 025 0 63 25 2T0 020 0 51 over 1 50 38 10 through 2 0 50 8 35 2T0 032 0 81 30 2T0 025 0 63 over 2 0 50 8 through 2 5 63 5 40 2T0 040 0 02 35 2T0 032 0 81 over 2 5 63 5 through 4 101 6 50 2T0 050 1 27 40 2T0 040 0 02 over 4 101 6 through 6 152 4 60 2T0 063 1 57 50 2T0 050 1 27 over 6 152 4 through 8 203 2 80 2T0 100 2 54 60 2T0 063 1 57 over 8 203 2 through 10 254 100 2T0 126 3 20 80 2T0 100 2 54 over 10 254 through 12 304 8 120 2T0 160 4 06 100 2T0 126 3 20 over 12 304 8 through 16 406 4 160 2T0 250 6 35 120 2T0 160 4 06 over 16 406 4 through 20 508 200 2T0 320 8 13 160 2T0 250 6 35 HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 7 of 20 Arrangement Identification Markers The letters numbers and marks which are necessary to identity the film shall be provided in accordance with fig3 And the contents of identification markers shall be specified in accordance with the Instruction Fig 3 Arrangemment of Identification Markers Notes 1 L is a space between the boundary marks 2 F mark penetrameter on the film side 3 8 Placement Location Markers The dimensions of the Location Markers shall satisfy the requirements of para fig 4 The Location Markers shall be placed on the surface of the part being radiographed not on the HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 8 of 20 exposure holder cassette the indication of location markers on the radiographs is an evidence that the required coverage of the region being examined has been obtained The location markers shall be placed as following Location markers sketches are shown in fig 5 Fig 4 Location Markers 3 8 1 Single wall Viewing 3 8 1 1Source Side Markers a Flat components or longitudinal joints in cylindrical or conical components b Curved or spherical components whose concave side is toward the source and when the source to material distance is less than the inside radius of the component c Curved pr spherical components whose concave side is toward the source 3 8 1 2Film Side Markers The markers shall be placed on the film side when radiographing either curved or spherical components whose concave side is toward the source and when the source to material distance is greater than the inside radius 3 8 1 3Either Side Markers The markers shall be placed on either the source side or the film side when radiographing either curved or spherical components whose concave side is toward the source and the source to material distance equals the inside radius of the component 3 8 2 Double wall Viewing For double wall viewing at least location marker shall be placed on the source side surface adjacent to the weld for each radiograph HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 9 of 20 HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 10 of 20 Fig 5 Location Markers Sketches HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 11 of 20 3 9 Film Processing 3 9 1 Manual Processing The chemical composition of developer and fixer temperature and time shall be according to The recommended practice of manufacturer 3 9 2 Automatic Processing Following four solutions are required for automatic processing A Developer and Make up Solution B Fixed and Make up Solution C Bath Solution for Developing System D Bath Solution for Fixing System 3 10 Illuminator and Masks 3 10 1The illuminator must provide light of an intensity that will illuminate the average density areas of the radiographs without glare and it must diffuse the light evenly over the viewing area 3 10 2Mask should be available to exclude any extraneous light from the eyes of viewer when viewing radiographs smaller than the viewing port or to cover low density areas 3 10 3In order to obtain the necessary brightness through the radiograph at least 30 cd m2 the viewing equipment shall have the following illumination Table 6 Radiograph DensityMinimum Illumination 2 03 000 cd m2 3 030 000 cd m2 4 0300 000 cd m2 3 10 4 Viewing Room Subdued background lighting shall be provided such that the intensity shall not cause troublesome reflections shadows or glares on the radiograph 4 Check of Surface to be Radiographed Prior to starting of radiographic examination the examiner shall check or verify that the Surface to be radiographed satisfies the following conditions HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 12 of 20 4 1The reinforcement of butt welded joints is within the value specified in the applicable Code Section as shown in Table 7 Table 7 Material Thickness in mm Max Reinforcement Permitted in mm less than 3 32 t127 5 16 7 9 4 2 Any surface irregularities such as weld ripples undercut and surface roughness are removed to a degree that surface irregularities cannot mask or be confuse with the image of any discontinuity 5Examination Level NDE examiner shall perform the specific radiographic examination in accordance with the requirements of the instruction and shall record examination data on the RADIOGRAPHIC EXAMINATION RECORD 5 1 Radiographic Technique A single wall exposure technique shall be used for radiography whenever practical When it is not practical to use a single wall technique a double wall technique shall be used An adequated number of exposures shall be made to demonstrate that the required coverage has been obtained source weld and film shall be arranged in accordance with one of the geometries shown in table 8 5 2Direction of Radiation The direction of the central beam of radiation shall be centered on the area of interest whenever practical HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 13 of 20 5 3Set up for Exposure Level I or level II individual shall set up the equipment tools and materials for exposure in accordance with the examination instruction so as all requirements for radiograph will be met the set up information shall be truly and clearly recorded as described in paragraph 9 0 5 3 1 Film cassette Pentameter and Markers shall be placed in accordance with fig 3 Examiner who performs the exposure shall carefully insert the specified film into cassette and attach the B mark on its back 5 3 2 Where the density of radiograph through any area of interest may vary by more than 15 or 30 from the density through the body of the penetrameter and within the minimum and maximum allowable density ranges specified in Table 9 two penetrameters shall be used One shall be placed on the lightest area of interest and the other shall be placed on the darkest area of interest Table 9 Acceptable Min Max Density Density of Radiograph Method of Viewing Minimum Maximum Single 1 8 4 0 Composite 2 6 1 3 4 0 In addition to following requirements the density of radiograph through any area of interest shall be within 15 and 30 of the density through the body of the penetrameter Each radiograph of a composite set shall have a minimum density of 1 3 HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 14 of 20 Table 8 NoExposure Technical Radiographic Viewing Source Weld film arrangement Remarks 1 Single Wall Single wall Source Film For flat components 2Single Wall Single wall Source Film For Longitudinal Welds 3 Single Wall Single Wall Source For Circumferential Welds the convex side of the part is toward the Source 4 Single Wall Single wall Film For Circumferential Welds the convex side of the part is toward the source and source to material distance is Equal to the inside radius of the part HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 15 of 20 Table 8 cont d No Exposure Technical Radiographic Viewing Source Weld film arrangement Remarks 5 Double Wall Single Wall Qptional source Location For circumferential Welds or Tube Welds 6 Double Wall Single Wall Qptional source Location For circumferential Welds or Tube Welds 7 Double Wall Double wall source When pipe OD Less Than 3 1 2 in and IQI Placed on the Source Side HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 16 of 20 5 4 Exposure Geometry 5 4 1 Focus to Film Distance FFD shall meet the requirements of geometric unsharpened Ug as listed in Table 10 Table 10 Thickness of Material t mm Ug mm 76 101 1 01 101 1 75 The geometric unsharpness of the radiograph shall be determined in accordance with Ug Ft D where F source size the max projected dimension of the radiating source or focal spot in the plane perpendicular to the distance D from the weld or object being radiographed mm D distance from source of radiation to weld or object being radiographed mm t distance from surface side of the weld or object being radiographed to the film mm 5 4 2 For small tube butt welds which diameter equal or less than 89 mm double wall radiograph and double wall viewing technique may be used The recommendation for D and angle of inclination between radiation beam and welded section as follows D 600mm 10 15 5 4 3The direction of the central beam of radiation shall be perpendicularly centered on the area of interest except in 5 4 2 When special defects shall be discovered the special direction to be used shall be based on the examination instruction written by the level III Examiner 6 Film Processing The examiner shall develop the exposed films in accordance with the film processing procedure The processing data shall be recorded as described in paragraph 9 0 6 1 Manual Processing Sequence HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 17 of 20 developingstop bathingfixing 5 8 20 11 15 20 washingwettingdrying 30 10 15 60 6 2 For Automatic Processing Keys When the automatically controlled developer is used the exposed film shall be developed together with the unexposed film to monitor the effectiveness Do 0 2 6 3 Processing Quality Requirements The processed radiographs shall be free from mechanical chemical or other blemishes to the extent that they cannot mask or be confused with the image of any discontinuity in the area of interest of the object being radiographed Such blemishes include but are not limited to a fogging b Processing defects such as streaks water marks or chemical stains c Scraches finger marks crimps static marks smudges or tears d Loss of detail due to poor screen to film contact e false indications due to defective screens or internal faults 7 Evaluation of Radiographs 7 1Prior to evaluating the radiographs the NDE Level II or III shall check if the information in radiographing record and the exposure location drawing of the component or product are complete and correct 7 2Prior to being interpreted the radiographs shall be checked whether their own quality is Conformed to the specified requirements Otherwise the radiograph has to be retaken 7 3In addition to the requirements described in paragraph 6 3 the acceptable standard of Radiograph quality is as follows 7 3 1 Density Limitation The transmitted film density through the radiographic image of penetrameters and the area to be interpreted shall be within the limitations specified in Table 9 7 3 2 Identification Markers and Location Markers All of the necessary identification markers such as work number seam number film HTHTA0506 99 Revision 0 Radiographic Examination Procedure for Butt Welds Page 18 of 20 number etc Shown in Fig 3 and location markers shall be appeared in radiographic image They also can not mask the area of interest of the radiographs shall be in a distance at least 5 mm from the edge of the weld 7 3 3 B Mark The light image of B mark shall not appear on a darker background of the radiograph 7 3 4 Penetrameter Sensitivity The Penetrameter image must be clear and completion The designated wire of the wire type Penetrameter shall be displayed on the radiographs 7 4 Acceptance Standards for Welds Quality 7 4 1 Pressure Vessels Acceptance Stan