RT Technique Evaluation Report ... 2. Query No. - 154 rev.0, Dated 04.04.09.
Technique Parameters: 1. Size of weld joint - Dia. ... ASNT Level 3 RT,UT, PT &
MT.
RT Technique Evaluation Report Abstract: Technique evaluation of Radiographic Testing of circumference weld of 1 ½” Dia. Pipe / fittings using Double Wall Single Image (DWSI) technique.
Site Query Reference: 1. Sub-contractor 2. Query No.
- Burntisland fabrication Ltd - 154 rev.0, Dated 04.04.09
Technique Parameters: 1. 2. 3. 4. 5.
Size of weld joint Source Type of film used Technique No. of exposure
- Dia. 1 ½” x 5.1 WT: - Se 75, Focal spot size - 2.5 x 2.5, Effective Focal Spot size - 3.5 - Agfa D4 - Double Wall Single Image ( DWSI ) - 5
Technique Evaluation: The radiographic sample films of one complete weld joint has been reviewed and observed the following points: 1. Technique used is DWSI : Radiation pass through two walls and only the weld on the film side wall is viewed for acceptance on the radiograph. When complete coverage is required for circumferential welds, number of exposure / shot to cover the complete circumference with adequate overlap between the exposure. Source
Object
Film
2. Geometric Unsharpness (Ug) :
Source
Object
Source to Object Distance (SOD)
Object to Film Distance (OFD) Film Effective Focal Spot Size x OFD Ug =
3.5 x 5.1 =
SOD
=
0.413 mm
43.2
Ug (max) value allowed as per ASME V, Article 2 , T-274.2 is 0.51mm
Geometric Unsharpness Ug is within limit
3. IQI Sensitivity : Type IQI used: Wire type , 10 Fe EN, in accordance with EN 462-1 IQI sensitivity review status: Film -1 & 2 : Wire W13 (0.2mm) was visible with 50% confident level Film – 3,4 & 5 : Wire W13 (0.2mm) was visible with 100% confident level Least wire dia of IQI visible % of Sensitivity =
x 100 Penetrated Thickness
Considered penetrated thickness in accordance with ASME V para, T-276.2 (a) ie, Penetrated thickness = wall thickness + weld cap height + root penetration 0.2 % of sensitivity =
= 2.8 5.1 +1+1
4. Conclusion: Based on the above technical evaluation, the proposed DWSI technique used on Ø1 ½” x 5.1 mm WT is proves the achievement of required quality level. Suggest to use this technique, subject to the following notes to Bifab, Avoid the fouling of image of source side WT into the film side WT Make sure 100% confident level visibility of penetrameter wire -13 No. of exposure shall be minimum 5 as in the technique qualification.
Evaluated by, R.Baskar Project QS Engineer - Vetcogray ASNT Level 3 RT,UT, PT & MT AWS-SCWI CSWIP3.2
