Engineering Policy & Procedure

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1 FPD > Engineering > Global Standards Engineering Policy & Procedure Revision History Number: G2-4 Section: G Subject: Radiographic Examination Procedure 1.0 SCOPE This procedure specifies the requirements for radiographic examination of welds in accordance with ASME Code, Section VIII. 2.0 REFERENCE SPECIFICATIONS 2.1 ASME Boiler and Pressure Vessel Code Section V Section VIII 2.2 ASTM Specifications 2.3 ASNT. SNT-TC-1A 3.0 PERSONNEL QUALIFICATIONS 3.1 All nondestructive test personnel working to this specification shall be qualified in accordance with the requirements of the American Society for Nondestructive Testing SNT-TC-1A. 3.2 Records of all personnel qualifications shall be on file by the organization performing non-destructive examination. 4.0 GENERAL REQUIREMENTS 4.1 Surface Preparation Surface irregularities, including weld ripples or weld surface irregularities, both inner and outer, shall be removed by any suitable process to a sufficient degree that these irregularities cannot mask or be confused with discontinuities. (1 of 16)6/21/2010 2:03:10 PM

2 4.1.2 The finished surface of all butt-welded joints may be flush with the base material or may have reasonably uniform crowns, with reinforcement not to exceed that specified by the applicable weld requirements procedure. 4.2 Backscatter Radiation Check A lead symbol "B" with minimum dimensions of 1/2 inch in height and 1/16 inch in thickness shall be attached to the back of each film holder A light "B" image on a darker background of the radiograph indicates that backscatter is excessive and additional protection from backscatter is needed. The radiograph shall be considered unacceptable and must be retaken. 4.3 Identification Each radiographic film shall be identified by actual radiographic images with at lease the following: a) Manufacturer s identification or radiographic inspection vendor. b) View number (for repair work, the letter "R" shall follow the view number). c) Part number, heat number, manufacturing traveler or route sheet number (if applicable). d) Weld identification. e) Date Film location positions shall be marked on the surface of each part with low stress stamps or vibroetching. Restamping will be required if removal of the stamp location, during any processing, is performed. On material where stamping is not feasible, the radiographic shooting sketch shall so note. Thinwalled items (1/4 inch or less wall thickness) shall be vibroetched in lieu of low stress stamping. 4.4 Densitometers shall be used for assuring compliance with film density requirements and stepwedge calibration films shall be used for checking densitometer calibration. 5.0 EQUIPMENT AND MATERIALS 5.1 Film Radiographic film shall be per ASTM E Double film technique (two films per cassette) shall be used. One slow and one fast film per cassette may be used to cover two thickness of material. (2 of 16)6/21/2010 2:03:10 PM

3 5.2 All film shall be processed in accordance with Part III of Recommended Practice SE Intensifying screens may be used. 5.4 Penetrameters shall be either hole or wire type and shall be manufactured and identified in accordance with the requirements or alternatives allowed in SE-142 or SE-1025 (hole type) and SE-747 (wire type). 5.5 Viewing facilities shall provide subdued background lighting of an intensity that will not cause troublesome reflections on the radiographic film. Equipment used to view films shall provide a variable high intensity light source sufficient for the essential penetrameter hole to be visible for the specific density range. The viewing conditions shall be such that light from around the outer edge and through the low-density portions of the radiograph do not interfere with the interpretation. 6.0 CALIBRATION 6.1 Source Size The equipment manufacturer s or supplier s publications, such as technical manuals, decay curves, or written statements documenting the actual or maximum source size or focal spot, shall be acceptable as source size verification For X-ray machines operating at 320 kv and less, the focal spot size may be determined by the pinhole method. For Ir-192 sources, the focal spot size may be determined by ASTM E Densitometer and Step Wedge Film The density of the steps on a step wedge comparison film shall be verified by calibrated densitometer annually Densitometers shall be calibrated at least every 90 days during use in accordance with paragraph 5 of SE EXAMINATION 7.1 Radiographic Technique A single-wall exposure technique shall be used for radiography whenever practical. When it is not practical to use single-wall technique, a double-wall technique shall be used. Whatever technique is used, complete coverage must be attained In the single-wall technique, the radiation passes through only one wall of the weld, which is viewed for acceptance on the radiograph. (3 of 16)6/21/2010 2:03:10 PM

4 7.1.2 Double-Wall Technique For double-wall radiography, one of the following technique shall be used: a) Single-Wall Viewing For welds in components, a technique may be used in which the radiation passes through two walls and only the weld on the film side wall is viewed for acceptance. For circumferential welds, a minimum of three exposures taken 120 degrees to each other shall be made. b) Double-Wall Viewing 1. For welds in components 3 1/2 inches or less in nominal outside diameter, a technique may be used in which radiation passes through two walls and the weld in both walls is viewed for acceptance on the same radiograph. For double-wall viewing, only a source side penetrameter shall be used. 2. For welds, the radiation beam may be offset from the plane of the weld at an angle sufficient to separate the images of the source side and film side portions of the weld so that there is no overlap of the area to be interpreted. A minimum of two exposures taken 90 degrees to each other shall be made for each joint. As an alternative, the weld may be radiographed with the radiation beam positioned so that the images of both walls are superimposed. A minimum of three exposures taken at either 60 or 120 degrees to each other shall be made for each joint. 7.2 Selection of Energy of Radiation X-Radiation Except as provided in paragraph 7.2.3, the maximum voltage used in the examination shall not exceed the value shown in the voltage selection figures for ASME Section V. Article 2. For materials other than those shown in the figures, the requirements of paragraph shall apply Gamma Radiation Except as provided in paragraph the recommended minimum thickness for which radioactive isotopes may be used is as follows: (4 of 16)6/21/2010 2:03:10 PM

5 MINIMUM THICKNESS MATERIAL Ir 192 Co 60 Steel 0.75" ( mm) 1.50" ( mm) Cooper or High Nickel 0.65" (16.51 mm) 1.30" ( mm) Aluminum 2.50" (63.50 mm) --- The minimum recommended thickness limitations may be reduced when the radiographic techniques used demonstrate that the required radiographic sensitivity has been obtained When it is not practical to perform radiography in accordance with paragraph or 7.2.2, or when isotopes other that Ir 192 and Co 60 are used, the procedure shall be proven satisfactory by actual demonstration of penetrameter resolution on the minimum thickness of the material radiographed. 7.3 Direction of Radiation The direction of the central beam of radiation should be centered on the area of interest whenever practical. 7.4 Location Markers Location markers, which are to appear as radiographic images on the film, shall be placed on the part - not on the cassette - and their locations shall be marked on the surface of the part being radiographed or on a map in a manner permitting the area of interest on a radiograph to be accurately located on the part, and providing evidence on the radiograph that the required coverage of the region being examined has been obtained. Location markers shall be placed as follows: Single-Wall Viewing a) Source Side Markers Location markers shall be placed on the source side when radiographing the following: 1. Flat components or longitudinal joints in cylindrical or conical components. 2. Curved or spherical components whose concave side is toward the source and when the source to material distance is less than the (5 of 16)6/21/2010 2:03:10 PM

6 inside radius of the component. 3. Curved or spherical components whose convex side is toward the source. b) Film Side Markers Location markers shall be placed on the film side when radiographing curved or spherical components whose concave side is toward the source and when the source to material distance is greater that the inside radius. c) Either Side Markers Location markers may be placed on either the source side or film side when radiographing curved or spherical components whose concave side is toward the source and the source to material distance equals the inside radius of the component Double-Wall Viewing For double-wall viewing, at least one location marker shall be placed on the source side surface adjacent to the weld for each radiograph. 7.5 The designated penetrameter with essential hole or designated wire diameter shall be as specified in Table 1 and Table 2. TABLE 1 (US) MATERIAL THICKNESS, PENETRAMETER DESIGNATIONS AND ESSENTIAL HOLE OR WIRE DIAMETER Penetrameter Nominal Single- Wall Material Thickness Range Up to 0.25, inclusive Over 0.25 through Source Side Designation Essential Hole Wire Diameter Film Side Designation Essential Hole Wire Diameter 12 2T T T T (6 of 16)6/21/2010 2:03:10 PM

7 Over through T T Over 0.50 through 0.75 Over 0.75 through 1.00 Over 1.00 through 1.50 Over 1.50 through 2.00 Over 2.00 through 2.50 Over 2.50 through 4.00 Over 4.00 through 6.00 Over 6.00 through 8.00 Over 8.00 through Over through Over through Over through T T T T T T T T T T T T T T T T T T T T T T T T All Dimensions in inches TABLE 2 (Metric) MATERIAL THICKNESS, PENETRAMETER DESIGNATIONS AND ESSENTIAL HOLE OR WIRE DIAMETER Penetrameter Source Side Film Side (7 of 16)6/21/2010 2:03:10 PM

8 Nominal Single- Wall Material Thickness Range Up to 6.35, inclusive Over 6.35 through 9.53 Over 9.53 through Over through Over through Over through Over through Over through Over through Over through Over through Over through Over through Over through Over through All dimensions in mm Designation Essential Hole Wire Diameter Designation Essential Hole Wire Diameter 12 2T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T (8 of 16)6/21/2010 2:03:10 PM

9 7.5.1 Welds With Reinforcements The thickness on which the penetrameter is based is the nominal single wall thickness plus the estimated weld reinforcement not to exceed the maximum permitted by the weld requirements procedure. Backing rings or strips are not to be considered as part of the thickness in penetrameter selection. The actual measurement of the weld reinforcement is not required Welds Without Reinforcements The thickness on which the penetrameter is based is the nominal single wall thickness. Backing rings or strips are not to be considered as part of the weld thickness in penetrameter selection. 7.6 Use of Penetrameters Penetrameters shall be selected from either the same alloy material group or grade, as identified in SE-1025, or from an alloy material group or grade with less radiation absorption than the material being radiographed Placement of Penetrameter a) Source Side Penetrameter Penetrameters shall be placed on the source side of the part being radiographed except as permitted in paragraph 7.6.2(b) b) Film Side Penetrameter Where inaccessibility prevents placing the penetrameter on the source side, it shall be placed on the film side in contact with the part. A lead letter "F" at least as high as the penetrameter identification number shall be placed adjacent to or on the penetrameter, but shall not mask the essential hole where penetrameters are used. c) Penetrameter Location For Welds 1. Hole Penetrameters Penetrameters may be placed on or adjacent to the weld. The identification number and lead letter "F", when used, shall not be placed in the area of interest, unless geometric configuration makes it impractical to place the identification number and "F" outside the weld (9 of 16)6/21/2010 2:03:10 PM

10 2. Wire Penetrameters The penetrameters shall be placed on the weld so that the length of the wires is perpendicular to the length of the weld. The identification numbers and lead letter "F", when used, shall not be placed in the area of interest unless geometric configuration makes it impractical to place the identification number and "F" outside the weld d) Alternate Location For Penetrameters When configuration or size prevents placing the penetrameters as previously described, it may be placed on a separate block as provided in SE Number of Penetrameters For components where one or more film holders are used for an exposure, at least one penetrameter image shall appear on each radiograph. a) Multiple Penetrameters If the density requirement must be met by using more than one penetrameter, one shall be representative of the lightest area of interest and the other the darkest area of interest; the intervening densities on the radiograph shall be considered as having acceptable density. b) Shims Under Hole Penetrameters A shim of radiographically similar material to the weld metal shall be placed under the penetrameter, if needed, so that the radiographic density throughout the area of interest is no more than minus 15% from the radiographic density through the penetrameter. The shim dimensions shall exceed the penetrameter dimensions such that the outline of at least three sides of the penetrameter image shall be visible in the radiograph. (10 of 16)6/21/2010 2:03:10 PM

11 7.7 Geometrical Unsharpness 8.0 EVALUATION Geometrical unsharpness of the radiograph shall be determined in accordance with the formula: where: Ug = F d / D Ug = geometrical unsharpness F = source size: the maximum projected dimension of the radiating source (or effective focal spot) in the plane perpendicular to the distance D from the weld or object being radiographed. D = distance from source of radiation to weld or object being radiographed d = distance from source side of weld or object being radiographed to the film D and d shall be determined at the approximate center of the area of interest Material Thickness mm (in.)* Ug Maximum mm (in.) < 50 (< 2.0) 0.51 (0.02) (2-3) 0.76 (0.03) (3-4) 1.02 (0.04) > (0.07) * thickness on which the penetrameter is based 8.1 Quality of Radiographs All 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 object being radiographed. 8.2 Radiographic Density (11 of 16)6/21/2010 2:03:10 PM

12 8.2.1 Density Limitations a) Single Film Viewing 1. X-ray minimum, 4.0 maximum 2. Gamma ray minimum, 4.0 maximum b) Composite Viewing 1. Each film of the composite set shall have a minimum density of Maximum density for composite viewing is 4.0. c) A tolerance of ~ 0.05 in density is allowed for variations between desitometer readings Density Variation a) General If the density of the radiograph in the area of interest varies more than minus 15% or plus 30% from the density through the body of the hole penetrameter or adjacent to the designated wire of a wire penetrameter, within the allowable density ranges specified, then an additional penetrameter shall be used for each exceptional area or areas and the radiograph retaken. Density calculations should be rounded to the nearest 0.1 points of density. b) Shims When shims are used, the plus 30% density restriction may be exceeded, provided the required penetrameter sensitivity is displayed and the density limitations of paragraph are not exceeded. 9.0 ACCEPTANCE CRITERIA All indications and conditions shall be evaluated per applicable Flowserve Acceptance Standards or Procedures as noted on the Bills of Materials, Purchase Order or other engineering documentation DOCUMENTATION (12 of 16)6/21/2010 2:03:10 PM

13 10.1 A radiographic technique sheet shall be prepared for each item to be radiographed and shall include as a minimum: a) Radiographic procedure number and revision. b) Base material type and thickness, weld thickness, weld reinforcement thickness, as applicable. c) Film identification and location. d) Film manufacturer and type or designation, number of film in each cassette. e) Penetrameter type, size and location. f) Extent of coverage and areas of noncoverage. g) Type of source, effective focal spot or effective source size. h) Type and thickness of intensifying screens and filters. i) Blocking or masking techniques, if used. j) Source to object distance, distance from source side of object to film. k) Source location. l) Identification of parts by drawing number and/or part number. m) Acceptance criteria. n) Identification of welding process (es) (GTAW, SAW, etc.). o) Single or double-wall exposure. p) Single or double-wall viewing. q) Number of exposures. (13 of 16)6/21/2010 2:03:10 PM

14 10.2 A radiographic evaluation sheet (reader s sheet) shall be prepared to document the film review and shall include as a minimum: a) Film identification and view. b) Date of evaluation. c) Route Sheet number or Manufacturing Traveler, if applicable. d) Type, size, intensity of source and exposure time. e) Reference to acceptance criteria or standard. f) Evaluation and disposition of the material(s) or weld(s) examined. g) Inspector identification, qualification level, signature and/or stamp. h) Flowserve purchase order number. i) Radiographic procedure and technique sketch number and revision. T-292(b) requirement is met by reference of technique number on reader sheet RADIOGRAPHIC INSPECTION AND FILM APPROVAL Radiographic review and film acceptance will be performed by Qualified Level II or Level III Personnel. Customer review may also be required, when specified by the purchase order or other contract documents RADIOGRAPHIC FILM PROTECTION Each related series of radiographs or views shall be packed in suitable outer envelopes which protect the films and separate them from other parts or assemblies. Each view (one pair of films) shall be placed in a separate paper sleeve to prevent contact with other films of the series. Each envelope shall be labeled with the Flowserve job number, manufacturing route sheet number (if applicable), part number or name, and view numbers included. A copy of the signed reader s sheet and shooting sketch(es) shall be placed in each envelope. (14 of 16)6/21/2010 2:03:10 PM

15 Reviewed and Approved By Level III or Equivalent: Steven E. Frysinger ASNT RT Level III Certification No Click here for Level III Certification Documentation Issue Date: Issue By: Approved By: 31 December 1996 R. Aleman Revision Date: Revision Approved By: D. Coleman Michael Mueller Leader - Technical Standards Team Revision History Description Date By Add review and signature of Level III MLM Correct metric conversion in Table II MLM Renew Level III signature MLM Updates after Level III review 6.2.1, 10.1 (b), (d), (j), 10.2 (f) New paragraph 7.7 Geometrical Unsharpness MLM (15 of 16)6/21/2010 2:03:10 PM

16 FPD Global Standards This page was last modified 12/12/2006 by M. Mueller (16 of 16)6/21/2010 2:03:10 PM