(340351936) SOP Number PS-335 Revision No_ 0

SOP Number PS- Revision No: Page:

Additional Access : FSES, FSESA

STANDARD OPERATING PROCEDURE INSTRUCTION

ECOMS File: SPI.nsfAs of

03/15/2004

This document becomes

uncontrolled when printed.

This field value determines whether a document should appear in the JV view. Maintained by JV Role.

Title: RADIOGRAPHY OF GIRTH BUTT WELDS IN PRESSURE PIPING

Date Effective :10/26/2007

SOP Number: PS-335

Prepared By : N/A

Revised By: Tim Barkley

Supersedes : 10/24/07 Revision No:0

Department: Section: PROCESS SPECIFICATIONS

Revision Summary :(1) In paragraph 1.3, removed "These requirements pertain to engineered apparatus, (compressors and turbines) PAP's and YR Turbines". (2) Deleted paragraph 1.4 addressing endwall piping. (3) Revised paragraph 3.1 from Elliott to FS-Elliott Co. LLC.

Purpose:

Approval Section

Title Approval By Approval DateApproval:Approval: N/A Mike PoseyApproval:Approval:


1. Scope :

1.1 This specification covers the standards and procedures for radiographic examination of girth butt welds in pressure piping in accordance with the latest requirements of ASME B31.3.

1.2 Personnel performing examinations within the scope of this specification shall have training and experience commensurate with the needs of this specification. For this purpose, SNT-TC-1A Recommended Practice for Nondestructive Testing Personnel Qualification and Certification, [ latest revision ] may be used as a guide.

Rev. 1.3 All girth butt welds fabricated in accordance with Process Specifications 336 and336A shall be subject to random radiographic examination to the extent required by the Customer's Purchase Order or Specification. Lubrication drain piping is excluded from these requirements.

2. Procedure :

2.1 Surface preparation.

2.1.1 Material surface shall be conditioned if necessary by any suitable process to a degree that surface irregularities cannot mask or be confused with discontinuities.

2.1.2 Weld ripples or weld surface irregularities on both the inside (where accessible) and outside shall be removed if necessary by any suitable process to such a degree that the resulting radiographic image due to any irregularities cannot mask or be confused with the image of any discontinuity.

2.1.3 The finished surface of all butt welded joints may be flush with the surface of the pipe or may have a uniform crown, with external reinforcement or internal protrusion not to exceed the following:

Wall Thickness Reinforcement or Protrusion¼" (6mm) and under 1/16" (1.5mm) Over ¼" (6mm) thru ½"(12.5mm) 1/8" (3mm) Over ½" (12.5mm) thru 1" (25.4mm) 5/32" (4mm) Over 1" (25.4mm) 3/16" (4.5mm)

2.2 Techniques:

2.2.1 Single-wall, single-image technique.

2.2.1.1 The single-wall technique with single-wall viewing shall be used whenever practicable. This technique is especially applicable for welds in pipe with a diameter greater than 3.5 inches and when the interior of the pipe section is accessible. With this technique, the radiation source can be placed inside the pipe and the film outside, or the radiation source can be placed outside the pipe and the film inside.An adequate number of exposures shall be made to demonstrate that the required coverage has been obtained.

2.2.2 Double-wall, double-image technique.

2.2.2.1 The double-wall technique with double-wall viewing is applicable for welds in pipe

SOP Number PS- Revision No: Page: with a nominal outside diameter equal to or less than 3-½ inches. With this technique


the radiation passes through the pipe, and the image of the weld of both walls is projected on the same film. The image may be straight band by superimposing the weld from both walls on one another, or it may be an ellipse by offsetting the radiation source. When the images are superimposed, at least three exposures shall be made at 60 degrees to each other. A minimum of two exposures, taken at 90 degrees to each other is required when the images are projected as an ellipse on the film. However, caution must be exercised to assure that tees, welder stamp numbers, and piping identification letters are not projected into the area of interest. If this is a possibility, the elliptical technique should not be used.

2.2.3 Double-wall, single-image technique.

2.2.3.1 The double-wall technique, with single-wall viewing, is a technique that may be used

in which the radiation passes through two walls and only the weld on the film side wall is viewed for acceptance. An adequate number of exposures shall be made to demonstrate that the required coverage has been obtained. When completecoverage is required for circumferential welds, a minimum of three exposures, 120 deg. to each other, shall be made.

2.3 Radiographs

2.3.1 Radiographs shall be made using film classifications listed in para. T-231.1 of Article

2; ASME Section V.

2.3.2 Radiographs shall be free from mechanical, chemical, or other blemishes to the extent that they cannot mask or can be confused with the image of any discontinuity.

2.3.3 Radiographs shall have a film density, through the image of the appropriate penetrameter and the area of interest, of 1.8 minimum for singe viewing for radiographs made with X-ray source and 2.0 minimum for radiographs made with gammaray source. For composite viewing of double film exposure, the minimum density shall be 2.6. Each radiograph of a composite set shall have a minimum density of 1.3. The maximum density shall be 4.0 for either single or composite viewing.

2.3.4 Radiograph identification shall be used to produce permanent identification on the radiograph traceable to the contract, component, weld or weld seam or part number. In addition, the Manufacturer's name and the date of the radiograph shall be plainly and permanently included on the radiograph.

2.3.5 Radiograph location markers which are to appear as radiographic image on the film shall be placed on the part - unless size or configuration does not permit . In this case , the marker may be placed adjacent to the piece so that it is plainly visible in finished radiograph. All location markers shall remain in place during the entire examination. Placement shall be in accordance with Paragraph T-275 of ASME Section V.

2.3.6 As a check on back-scattered radiation, a lead symbol "B", with minimum dimensions of ½ inch (13mm) in height and 1/16 inch (1.6mm) in thickness, shall be attached to the back of each film holder. If a light image of the "B" appears on a darker background of the radiograph, protection from backscatter is insufficient and the radiograph shall be considered unacceptable. A dark image of the "B" on a lighter background is not cause for rejection.


2.4 Screens:

2.4.1 Intensifying screens may be used, except that fluorescent type screens are not


permitted.

2.5 Energy of Radiation:

2.5.1 Radiography may be X-ray machine, Iridium 192, or Cobalt 60.

2.5.2 The selection of energy of radiation shall be in accordance with paragraphs T-272.1, and T-272.2 of ASME Section V Article 2.

2.6 Penetrameters:

2.6.1 Penetraments shall be either the hole type or the wire type and shall be manufactured and identified in accordance with the requirements or alternates allowed in SE-142 or SE-1025 (hole types) and SE-747 (wire types) and Appendices of ASME Section V.

2.6.2 ASME penetraments shall consist of those in Table 1 for hole type and those in Table

2 for wire type.

2.6.2.1 The designated hole penetrament with essential hole or designated wire diameter shall be as specified in Table 3. A smaller hole in a thicker penetrameter or a larger hole in a thinner penetrameter may be substituted for any section thickness listed in Table 3 provided equivalent penetrameter sensitivity is maintained and all other requirements for radiography are met. Refer to ASME Section V Non-Mandatory Appendix B, Table B-220, Column 2T for approximated equivalence between hole and wire penetrameters.

2.6.2.2 For welds, the thickness on which the penetrameter is based on is the nominal single-wall thickness plus the permitted reinforcement.

2.6.3 The penetrameter sensitivity shall be displayed on the radiograph by the penetrameter image and the specified hole or designated wire thickness.

2.6.4 For double-wall viewing, the penetrameter shall be placed on the source side. Where inaccessibility prevents placing the penetrameter in the source side and forsingle-wall viewing, the penetrameter shall be placed on the film side and a lead letter "F" at least as high as the identification number shall be placed adjacent to the penetrameter.

2.6.5 A shim of material radiographically similar to the weld metal shall be placed under the penetrameter if the weld reinforcement and/or backing strip are not removed. The shim dimensions shall exceed the penetrameter dimensions such that the outline ofat least three sides of the penetrameter image shall be visible in the radiographic. Shims apply only to hole type penetrameters.

2.6.5.1 The penetrameter shall be placed adjacent to the weld seam. Ideally, the penetrameter should be 1/8" to 1/2" (3mm to 13mm) from the toe (edge) of the weld.

2.6.5.2 When configuration or size prevents placing the penetrameter on the object being radiographed, it may be placed on a separate block as provided in SE-142. When the penetrameter is placed on a separate block, the penetrameter shall be placed on shims of radiographically similar material as the weld and of the same thickness as the total weld thickness, and shall be positioned as closely as possible to the pipe, and shall be level with the top surface of the pipe.


2.6.6 A minimum of one penetrameter shall be used for each radiograph. Each penetrameter shall represent an area of essentially uniform radiographic density. If


the density of the radiography anywhere through the are of interest varies by more than minus 15 or plus 30 percent, then an additional penetrameter shall be used for each exceptional area. When shims are used, the plus 30 percent density restriction may be exceeded provided the required penetrameter sensitivity is displayed and the density limitations of para. 2.3.3 are not exceeded.

2.6.6.1 A minimum of three equally spaced penetrameters shall used when the source is placed on the axis of the object and a complete circumference radiographed with a single exposure.

3. Radiographic Examination:

Rev. 3.1 Radiographic examination shall be either 100%, random, or spot as agreed upon between the Customer and FS-Elliott Co., LLC.

3.2 "100 Percent Radiography" is defined as radiographic examination of the complete circumference of all the girth butt welds in a designated lot of piping.

3.3 "Random Radiography" is radiographic examination of the complete circumference of a specified percentage of the girth butt welds in a designated lot of piping.

3.4 "Spot Radiography" is radiographic examination by making a single exposure of a specified percentage of the girth butt welds in a designated lot of piping.

3.4.1 For spot radiography in piping 2-½ inches NPS and smaller, a single elliptical exposure is taken which encompasses the entire weld circumference.

3.4.2 For spot radiography in piping larger then 2-½ inches NPS, a single exposure is taken which contains at least 25 percent of the inside circumference or 6 inches(150mm), whichever is less.

3.5 A designated lot of piping shall consist of the piping for one unit or shop order. On larger jobs, it may be advantageous to subdivide a designated lot. When this becomes desirable, it will be a matter of agreement with the Purchaser's inspection.

3.6 The selection of welds to be random or spot radiographed shall represent each welder's or welding operator's work, though not necessarily each type of weld (procedure), in a designated lot.

4. Acceptance -Rejection Standard:

4.1 Limitation on imperfections in pressure piping welds shall be as stated in Table 4.

4.2 When the examination of a spot or random type reveals a defect requiring repair, two additional welds by the same welder in the same designated lot of piping shall be examined.* If the second group of welds is acceptable, all welds represented by them shall be accepted. For each of the second group of welds which reveals defects requiring repair, two additional welds by the same welder in the same designated lot of piping shall be examined.* If all of the third group of welds areacceptable, all welds represented by them shall be accepted. If any of the third group of welds reveal defects requiring repair, all welds by this welder in the same designated lot of piping shall be fully examined and repaired as necessary or replaced. For purposes of repairs, the work of each individual welder shall be considered a subdivision of a designated lot.


*Note: Additional examinations are not required if all the welds in the designated lot made by this welder have been examined.

5. Repairs :

5.1 Repaired welds which are found unacceptable on radiography must again be repaired. Since all repair welds will be fully radiographed, any rejections will not require additional welds to be examined as provided in 4.2 above.

6. Report of Examination:

6.1 A written report shall contain the following information:

1. Shop order or job number.2. RT number.3. Type of radiation source.4. Type of film - single or double-loaded cassette.5. Type of screens and filter.6. Source to film distance.7. Exposure time.8. Penetrameter.9. Sensitivity.10. Drawing or sketch showing setup used.11. Review form with record of interpretation of each radiograph and

disposition of weld examined.12. Material and thickness range.13. Source size.14. X-ray voltage (if applicable).



(Continued...)


(Continued...)


END OF DOCUMENT

Documents

(340351936) SOP Number PS-335 Revision No_ 0