射线检查程序RADIOGRAPHICEXAMINATIONPROCEDURE.doc

RADIOGRAPHIC EXAMINATION PROCEDURE3210REVISIONPREPARED BYREVIEWED BYAPPROVED BYAl1・ General(l) This procedure is applied to the x-ray radiographic examination of welds for pressure vessels in accordance with ASME Code Section I、Section V and Section VIII Division 1&2.(li) This procedure is used to defect discontinuities in ferrous welds and waterial with a thickness range between 4 mm and 50.8mm.2. Qualification of Examination Personnel2.1 Any person engaged in the radiographic examination shall be qualified and certified as a radiographic examiner in accordance with "Written Practice for NDE Personnel Training, Examination, Qualification and Certification2.2 Radiographers shall be at least level I , Radiographic inteipreters shall be at least level II.3. Equipment, Tools and Materials3.1 x-ray equipment shall be selected from Table 1.Table 1TypeManufactoryMax. TubeVoltage (kVp)Max. TubeCurrent (mA)Focus・ Size(mm)Permitted max. material thickness (mm) (steel)3OOEG-S3R1GAKVCORPORATION30052.5x2.550250EG-S3RIGAKVCORPORATION25052.0x2.0303.2 Film3.2.1 Film selection shall be in accordance with ASTM E-1815, Standard Test Method for Film Systems for Industrial Radiography. The classification table of film shall be provided by the film manufacturer. Film system classes Special, I , II ,III,W-A, and W-B are permitted. Depending on the x-ray penetration thickness, a suitable film shall be selected .When using two films method; two different types of film shall be selected.3.2.2 Film KODAK AA 400 may be used.3.3 Intensifying ScreensA suitable lead screen shall be selected from Table 2.Table 2Tube VoltageThickness of lead Screen (mm)FrontBack<150 kVp0.030.03150〜300 kVp0.030」03.4 Densitometer and Step Wedge Calibration Film3.4.1 The transmission densitometer listed in Table 3 shall be used for judging radiograph density. The densitometer shall be calibrated against the step wedge calibration film at least every 90 days during use by the NDE Level II or III Examiner, in accordance with "DensitometerCalibration Procedure^^・ The step wedge calibration film shall have been verified within the last year by comparison with a national standard step tablet.Table 3TypeManufactoryMea. RangeMea.,PrecisionTD-210AZhejiang Wenzhou non-destructive testing instrument factory0.00-4.00D±0.03D3.4.2 Periodic calibration verification checks of the densitometer and the step wedge calibration film shall be performed per 3.5 Image Quality Indication (IQI)3.5.1 Type and material of IQIs3.5.1.1 The wire type IQI presented as Fig. 1 and Tab.4 shall be used・ The wire type IQI shall be manufactured and identified in accordance with the requirements in SE-747・3.5.1.2 The wires shall be fabricated from material or alloy with same or less radiation absorption than the material being radiographed・Table 4 Wire IQI Sizes and wire Identity NumbersWire Diameters in.(mm)Set AWire IdentitySet BWire Identity0.0032(0.08)10.010(0.25)60.004(0.1)20.013(0.33)70.005(0.13)30.016(0.41)80.0063(0.16)40.020(0.51)90.008(0.2)50.025(0.64)100.010(0.25)60.032(0.81)113.5.2 IQI Selection3.5.2.1 The designated essential minimum wire diameter shall be as specified in Table 5.Table 5 IQI SELECTIONNominal Single-WallMaterial ThicknessRange, in (mm)Source Side IQIFilm Side IQIEssential WireDiameter in.(mm)WireIdentityEssentialWire Diameter in.(mm)WireIdentity<0.25 (<6.4)0.008(0.2)50.006(0.16)4>0.25 〜0・375(>6.4〜9.5)0.010(0.25)60.008(0.2)5>0.375〜0・5(>9.5-12.7)0.013(0.33)70.010(0.25)6>0.5 〜0・75(>12.7-19.1)0.016(0.4)80.013(0.33)7>0.75 〜l・00(>19.1-24.5)0.020(0.51)90.016(0.41)8> 1.00-1.50( >25.4-38.1)0.025(0.64)100.020(0.51)9> 1.50-2.00( >38.1-50.8)0.032(0.81)110.025(0.64)103.5.2.2 For welds with reinforcements, the thickness on which the IQI is based is the nominal single wall thickness plus the estimated weld reinforcement not to exceed the maximum permitted by the SectionVIII Division 1 ・ For welds without reinforcements, the thickness on which the IQI is based is the nominal single wall thickness・ In both cases backing rings or strips shall not be considered as part of the weld thickness in IQI selectio n.3.5.3 Placement of IQI(s)The IQI(s) shall be placed on the source side of the part being examined・ When configuration or size prevents placing the IQI(s) on the part or weld, the IQI(s) may be placed on a separate block in compliance with Para.T-277.1 of Section V. ASME. The separate block shall be placed as close as possible to the part being radiographed・Where inaccessibility prevents hand placing the IQI(s) on the source side, the IQI(s) shall be placed on the film side in contact with the part bei。