TRANSPORTADORA DE GAS DEL PERU

Transcription

1 Page 1 0 ISSUE FOR CONSTRUCTION GIU BOF GIU B ISSUE FOR APPROVAL GIU BOF GIU A ISSUE FOR APPROVAL GIU BOF GIU REV.. DESCRIPTION DATA PROJ. EXEC. CONT. APROV. TRANSPORTADORA DE GAS DEL PERU TGP COMPAÑÍA TÉCNICA INTERNACIONAL AREA TECHINT TEDUC THIS DRAWING IS A PROPERTY OF TECHINT COMPANIA TECNICA INTERNACIONAL AND IS NOT ALLOWED TO BE DISCLOSED, COPIED OR MODIFIED WITHOUT ITS PREVIOUS WRITTEN AUTHORIZATION. 0 ESC. S/E JOB: E REVISION

2 Jb: E TABLE OF CONTENTS 0.0 PURPOSE 1.0 SCOPE 2.0 REFERENCE CODES AND STANDARDS 3.0 WELDS TO BE TESTED 4.0 RADIOGRAPHIC EQUIPMENT 5.0 RADIOGRAPHERS 6.0 CHARACTERISTICS OF THE RADIOGRAPHIC PROCEDURE 7.0 FILM PROCESSING 8.0 PRODUCTION 9.0 SAFETY CONDITIONS 10.0 ACCEPTANCE CRITERIUM AND TEST FOR RADIOGRAPHIC EVALUATION

3 Jb: E PURPOSE This specificatin establishes the general guidelines fr pipe weld radigraphic test thrugh the use x-rays r gamma rays, t assure a prper radigraphic quality SCOPE This specificatin shall cver all pipeline and piping welds under inspectin with the fllwing general cnditins acceptance and refusal welds stated in API REFERENCE STANDARDS Radigraphic tests perfrmed n welds alng Pipeline and Facilities cnstructin must fulfill the specificatin requirements and thse the cdes and standards mentined belw. Unless therwise indicated, the latest issues such cdes and standards shall apply: ASME B 31.8 / B 31.4 API Std. 04 ASNT-TC-1ª / ASNT CP 189 ASME E WELDS TO BE TESTED 3.1 On line welds: Owner Inspectr shall chse the welds t be radigraphed, hwever the percentage stipulated must be cmpleted during that day. All pipeline welds must be radigraphied at 100%. Radigraphic examinatin piping welds fr facilities shall be dne in accrdance with the prject piping Specs One hundred percent (100%) tie-ins and special wrks must be tested, including but nt limited t rads, rivers, railways, third party crssings and previusly repaired welds.

4 Jb: E Radigraphic tests will be perfrmed n the whle circumferential welding, in cmpliance with API Standard 04, Sectin 8. Whenever it is nt pssible t perfrm radigraphic tests due t weld gemetry, cntrl welds shall be carried ut thrugh ther nn-destructive methds (magnetic particle testing, liquid penetrant testing, ultrasnic testing, hydraulic test, etc.). The alternative methds shall be in accrdance with written prcedures and must be previusly apprved by Owner The radigraphic image shall be interpreted in accrdance with the Acceptance standards established in applicable cde 3.4 Owner Inspectr must be able t cntrl all radigraphs. Fr such reasn, all expsed films must be made available t him. 3.5 Any repairs made will be at the Supplier s expense. 3.6 A radigrapher (at least Level II) shall interpret the radigraphs crrespnding t prductin welds, nce the films are cmpletely dry. 3.7 All radigraphs nt fulfilling the specificatin requirements, regarding image quality, shall be retaken. Such cnditin must be indicated in the gamma ray testing reprt (GTR). 3.8 The weld surface t be radigraphically tested must be free frm irregularities n bth sides the weld, in rder t achieve a crrect interpretatin the radigraphs. If necessary, all buckling and irregularities will be eliminated, s as t avid the cncealment any defects. 3.9 The transitin the metal depsited by welding n the base metal surface must be dne stly, s that n ntch defects are prduced RADIOGRAPHIC EQUIPMENT The Cntractr shall have the fllwing minimum necessary equipment and material at the site t achieve the perfect executin prductin weld radigraphic tasks. 4.1 The Cntractr may use X rays r gamma rays fr radigraphic equipment Gamma ray : Surce : Iridium 192 Strength Surce : minimum curies maximum curies

5 Jb: E External equipment r internal equipment ( crawlers ) may be used X ray : If X ray crawler is used, the expsure vltage shall be accrding t pipe thickness, and shall be advised in a Specific Radigraphic Prcedure. 4.2 The Cntractr shall have at the site the mbile units fr radigraphy prcessing and interpretatin. All equipment used fr the perfrmance radigraphic activities, film prcessing, interpretatin, etc. must be in perfect perating cnditin. Any element nt cmplying with prductin requirements will be replaced. 4.3 Radigraphic Film and prcessing material The film t be used must be extra fine grain Class 1, r fine grain Class 2 as needed. The films must be fresh and be within the life term specified by the manufacturer The films must be rllpack type r similar. Whenever mre than ne film is used t inspect a weld, adjacent films shall verlap in rder t assure cntinuity cntrl alng the whle circumferential seam in such a way t ensure that n part the weld has been mitted. Film verlap shuld nt be less than 2. Develpment prcessing materials shall be thse recmmended by a film Manufacturer 4.4 Intensifying screens Minimum 20-μm thick lead intensifying screens will be used with gamma rays (Ir-192). Lead screens must be kept free frm scratches, wrinkles, pitting and xide particles. 4.5 Image Quality Indicatrs (IQI) IQI ASTM E 747 shall be used as indicated in API Standard 04 fr pipeline r in accrdance with ASME V fr piping Whichever the type IQI used, the radigraphic technique must detect the defects having a depth equal t 2% (vertical sensitivity) and a width 4% (lateral sensitivity) the ttal radigraphed thickness.

6 Jb: E The IQIs shall be in direct cntact with the pipe, and the number IQIs t be placed shall be in accrdance with API Standard 04, Sectin 8 fr pipeline r in accrdance with ASME V fr piping. 4.6 Film density Radigraphic images shall nt be less than 1,8 thrugh the maximum thickness weld prtin and nt shuld it exceed 3.5 thrugh the base metal (thrugh small lcalized areas may have up t maximum densities shall nt exceed 4,2) The Radigraphic Cntractr shall have a densitmeter with a valid crsschecking certificate at each wrk spread, t cntrl the expsed film density. 4.7 Darkrm The Cntractr shall have a rm t carry ut all film prcessing, develpment, fixing, washing and drying peratins, as well as srting there prir t interpretatin Such darkrm shall at least: Prevent light frm entering the rm. Have adequate ventilatin and heating. Be a dry place. Have necessary water and electric pwer supply. Have tw separate lighting systems: a white light system and a system lamps with adequate filters. Have the necessary elements t enable expsed film prcessing and drying RADIOGRAPHERS 5.1 All persnnel perfrming radigraphic tests r interpreting the films under this Specificatin shall be qualified and authrized as established in ASNT-TC-1A and this Specificatin. The Cntractr shall submit the radigrapher s persnal backgrund tgether with a qualifying certificate t Techint S.A. prir t the cmmencement prductin activities. 5.2 Only Level II and III radigraphers shall interpret the radigraphic images. 5.3 Level I radigraphers shall nly perfrm the assembly the radigraphic installatin, make the expsures r prcess films under the supervisin a Level II r higher technician.

7 Jb: E Techint must send t Owner, the qualifying certificate each the radigraphers prir t starting any prductin radigraphy. The qualificatin recrd each radigrapher must be cmplete. It must include the name the authrized entity participating in such qualificatin and a descriptin all the prcedures fr which it has been apprved. Such certificate shall be valid fr 3 years. 5.5 Persnnel Re-qualificatin Qualificatin recrds that are incmplete, illegible r smehw questinable, re-qualificatin the radigrapher shall be requested If there are any reasns t questin the abilities any the radigraphers, re-qualificatin there may be requested RADIOGRAPHIC PROCEDURE 6.1 The Cntractr must cmply with the Radigraphic Specificatin t be used at the site and issue a Specific Radigraphic Prcedure (SRP) fr each diameter, thickness and technique, fr apprval. By mutual agreement it will be decided whether the prcedure qualificatin shall be perfrmed n a test weld r a prductin weld. 6.2 If the SPR is qualified n a test weld, the pipe must have the same size and wall thickness than the ne t be used fr prductin welds. Besides, the material shuld have similar radigraphic characteristics. 6.3 Field qualificatin shall require at least 3 radigraphs being taken the test weld. IQIs placed n bth the surce side and the film side shall be used. Each IQI shall be identified and they must be lcated at 1 frm the film edge. Bth IQIs must have the required sensitivity. Weld defects shall be recrded in a gamma ray test reprt. Upn test cmpletin, the Inspectr shall determine whether the prcedure is satisfactry. 6.4 The Specific Radigraphic Prcedure shall be re-qualified if there have been any changes t: The type jint. The radiatin surce. The pipe diameter, if such change amunts t twice r half the qualified size. The surce angle (by mre than 15 degrees).

8 Jb: E The pipe thickness, if such change amunts t twice r half the qualified size. The film type. Intensifying screens. 6.5 If the image ne the IQIs is nt clear enugh r the radigraphs are nt within the acceptable density range r they are nt in full accrdance with this Specificatin, the Specific Radigraphic Prcedure shall nt be qualified. Upn the executin the necessary adjustments, the prcedure qualificatin shall be repeated. 6.6 Expsed Film Identificatin Expsed films shall be clearly identified by the use lead numbers and letters The films each weld must shw the welder s number, the jb number, date when the radigraph was taken, the pipe diameter, weld number and the pipeline sectin identificatin The Radigrapher Cntractr shall mark 0 and the weld number n the pipe with indelible paint. Films shall be identified as indicated in Wrk Instructin 2794 L-ME FILM PROCESSING 7.1 Films shall be stred in a cl and dry place. 7.2 Enugh water and chemicals shall be prvided s as t keep the film clarity. 7.3 The materials and equipment used fr film handling and develping, including cleaning, shall be subjected t the inspectr s apprval. 7.4 Either autmatic r manual film prcessing may be used. If autmatic prcessing is used, manual prcessing shuld als be available. Film prcessing shall be carried ut preferably in tanks, where the films placed in their respective film hlders may be intrduced vertically r by means autmatic prcessrs. 7.6 The develpment bath temperature must be cntrlled t assure it is within the values recmmended fr the type film used. 7.7 The water supply necessary t carry ut the final wash must be enugh t enable quick perfrmance such task. If washing is dne in tanks, it will be necessary t renew the water cntinuusly s as t drag ut the chemicals cming frm the fixing bath and thus prevent washing bath cntaminatin.

9 Jb: E Films shall be preferably dried with dust-free ht air r autmatic dryers. 7.9 Film defects Films must be free any defects which might detrimentally affect the crrect interpretatin radigraphs Films shall nt be fit fr interpretatin when ne the fllwing defects are detected: Fgged parts. Scratched parts. Fading due t defective fixing r washing. Pints r stains caused by water drps. Damaged emulsin due t film frictin. Flds, scratches r any ther type marks Radigraphs rejected due t the abvementined defects shall be repeated FILM VIEWING EQUIPMENT (Iluminatr) A iluminatr shall be available fr radigraph reading and interpretatin. Its variable high intensity type must enable the viewing film densities within the specified ranges, making the bservatin the radigraphic image easy PRODUCTION 8.1 Radigraphic interpretatin shall be carried ut in accrdance with the acceptance standards established in the applicable cde. The Inspectr shall reject any radigraphs nt cmplying with the requirements the abvementined standard and thse this Specificatin. 8.2 The fllwing, amng thers, shall be grunds fr rejectin: Alteratin identificatin. Incmplete cverage the circumferential seam. Imprper density. Lead letter which darken the weld area. Fg, prcessing stains, scratches r any ther factr detrimentally affecting the crrect weld evaluatin.

10 Jb: E All defects detected shall be reprted t the Inspectr well in advance in rder t enable the crrespnding repairs and further cntrl befre the pipe is lwered int the trench. 8.4 Each radigraphic interpretatin shall be recrded in a standard frm, which shall becme a part the final site dcuments. 8.5 Radigraphs taken repairs shall be identified with letter R, s that they can be differentiated frm the riginals. 8.6 The final interpretatin radigraphs shall include verificatin their density and definitin. 8.7 The Radigraphy Cntractr shall submit Techint SACI a written reprt with the final results the radigraphic inspectin welds, tgether with the radigraphs taken. 8.8 Accrding t the needs arising frm the wrk perfrmed, a partial reprt will be made n a daily basis and submitted t Owner Representative and Cntractr. Hwever, upn cmpletin wrk, a final reprt shall be issued. Such reprt shall include all data appearing n partial reprts. 8.9 All reprts made shall be clear and legible, and shall cntain all the fllwing: Indicatin the radigraphed jint r area and Welder number. Interpretatin radigraphs, stating the type defects bserved and whether the radigraph might be rejected due t such defects. Cde r standard used fr inspectin. Radiatin surce used. Size gamma radiatin surce. Fcus-film distance. Brand, type and size film used. Material specificatin. Acceptance standard. Pipe diameter and thickness The final authrity in determining the defects detected thrughut the weld radigraphic cntrl shall be the Radigraphy Level II r III.

11 Jb: E SAFETY CONDITIONS 9.1 Radigraphy experts and any ther persnnel invlved in radigraphic activities shall carry a dsimetric film and a pcket dsimeter. Care shall be taken t prevent persnal radiatin frm exceeding the limits established by the regulatins in frce. 9.2 A Geiger meter shall be available fr all gamma ray r X ray equipment. When gamma ray surce is nt being used, it shall be kept in a metallic lcked cntainer with radiactive signs, fixed utside the mbile darkrm unit. Access shall be permitted t radigraphy persnnel nly. It is the Radigraphy Cntractr s respnsibility t prevent unauthrized peple frm entering the radigraphic test areas. The Radigraphy Cntractr shall have an Emergency Prcedure fr accidents ccurred during the perfrmance radigraphic tests. A cpy such prcedure shall be delivered t Techint SACI prir t the initiatin radigraphic activities. Signs as flashing lights, flags, etc will be established at safe intervals t warn all persnnel when radigraphy is in prgress. ACCEPTANCE CRITERIUM AND TEST FOR RADIOGRAPHIC EVALUATION Standards as per API 04 September 1999 editin fr pipeline ASME cde B31.8/ B31.4/ B31.3 as applicable fr piping ANNEX Specific Radigraphic Prcedure (SRP)