14.1.1 All required Nondestructive Examination (NDE) shall be performed in accordance with inspection procedures that are in complete compliance with ASME SEC V and this specification. This written procedure shall address each inspection method and technique used including
acceptance criteria. When required by the purchase order or this specification the procedure(s) shall be submitted to Saudi Aramco Inspection Department for approval.
14.1.2 All Nondestructive Examination, including Magnetic Particle and Liquid Penetrant examinations, shall be performed by personnel certified in accordance with ASNT CP-189, or equivalent National Certification Programs that has been approved by the Saudi Aramco Inspection Department. Personnel responsible for interpretation of Nondestructive Examination results shall be certified to a minimum of Level II.
14.1.3 All required NDE for final acceptance of the vessel shall be performed after the completion of all welding and repairs and prior to pressure testing. In vessels requiring PWHT, all NDE for final acceptance shall be performed after the final PWHT.
14.1.4 All pressure and non-pressure welds shall be visually inspected where accessible. All segments of longitudinal, circumferential or built-up head pressure weld seams covered or rendered inaccessible by internals, lifting lugs or other attachments shall be fully radiographed over the entire affected length plus minimum 5 cm (2 inches) either side prior to installation of the attachment.
14.1.5 Magnetic particle examination or liquid penetrant examination per the applicable Code shall be performed on the surfaces of hot formed and reheat treated parts.
14.2 Radiographic Examination
14.2.1 All radiography shall be performed with intensifying screens. Only lead or lead foil (fluoro-metallic) screens shall be permitted unless otherwise approved by the Saudi Aramco Inspection Department.
14.2.2 Tungsten inclusions in Gas Tungsten Arc welds shall be evaluated as individual rounded indications. Clustered or aligned tungsten
inclusions shall be removed and repaired.
14.2.3 Radiography examination requirements for weld joints categories A, B, C and D shall be according to Table 1 of this specification and the following:
a) Butt welds connecting forged junction ring, conforming to ASME SEC VIII D2, Figure 4.2.4(e), to shell and head shall be 100% radiographed. Use of ultrasonic examination method that generates permanent records can be used as a substitute to radiography, as applicable (see relevant requirements per Note 3 of Table 1).
b) Butt welds in multi-piece plate blanks to be formed into heads shall be 100% radiographed after forming. Use of ultrasonic examination method that generates permanent records can be used as a substitute to radiography (see relevant requirements per Note 3 of Table 1).
14.2.4 100% radiography examination is required for the following weld joints:
a) Butt welds connecting skirt to forged junction ring, conforming to ASME SEC VIII D2, Figure 4.2.4(e).
b) Butt welds connecting skirt to weld build-up construction at vessel-to-skirt junction per paragraph 10.2.9 of this specification.
c) Butt welds connecting forged junction ring according to ASME SEC VIII D2, Table 4.2.5 - Detail 7 to shell and head.
14.3 Ultrasonic Examination
14.3.1 Ultrasonic examination requirements for weld joints categories A, B, C and D shall be according to Table 1 of this specification.
14.3.2 All plates with thickness more than and including 50 mm (2.0 inches) shall be ultrasonically examined by the Vessel Manufacturer in accordance with ASTM SA578. Acceptance criteria shall be Level C of SA-578.
14.3.3 Plates with thickness more than 12.5 mm (0.5 inch) and less than 50 mm (2.0 inches) shall be ultrasonically examined by the vessel manufacturer in accordance with ASME SA-435. Any area where one or more discontinuities produce a continuous total loss of back
reflection accompanied by continuous indications on the same plane (within 5% of plate thickness) that cannot be encompassed within a 25 mm (1 inch) diameter circle is unacceptable.
14.3.4 100% Ultrasonic examination is required for the following weld joints:
a) Butt-welds in vessel supports.
c) Full-penetration welds in external attachments (supports, brackets, lugs, etc.) to pressure retaining parts.
14.3.5 All forgings shall be 100% ultrasonically examined by the equipment manufacturer in accordance with ASME SA388. Acceptance criteria shall be in accordance with ASME SEC VIII D2, paragraph 3.3.4.2.
Indications per ASME SEC VIII D2, paragraphs 3.3.4.3 and 3.3.4.4 are not acceptable.
14.3.6 100% ultrasonic examination is required for welds attaching vessel directly to skirt and conforming to ASME SEC VIII D2,
Figures 4.2.4(a), 4.2.4(b) and 4.2.4(c). Where ultrasonic examination cannot be utilized, due to only construction geometric configuration, the whole joint shall be either magnetic particle (MP) or liquid penetrant (LP) examined after each 6 mm depth of weld deposit and the finished weld surface.
14.3.7 100% conventional ultrasonic examination is required for all full penetration welds in vessel supports. Alternatively, 100% radiography examination shall be used.
14.3.8 Weld build-ups construction at vessel-to-skirt junction per paragraphs 10.2.9 and 10.2.10 of this specification shall be 100% ultrasonically examined.
14.4 Magnetic Particle Examination
14.4.1 Permanent magnetic yokes are not permitted.
14.4.2 Prods are not permitted for use on air-hardenable materials, materials that require impact testing, and on the fluid side of pressured
components for vessels in wet sour service.
14.4.3 Except for non-Ferro magnetic materials, magnetic particle
examination using an AC yoke is required for the following welds:
a) Pressure containing weld joints categories A, B, C and D per Table 1 of this specification.
b) Welds in vessel support (skirt, saddle, lug, and leg) c) Attachment welds to the pressure vessel
d) Areas where temporary attachments have been removed e) Arc strike areas
Internal welds shall be examined with Wet fluorescent MPI. External welds shall be examined with wet visible MPI or Wet fluorescent MPI.
Note: If wet visible MPI is used, a white color contrast coating shall be applied prior to the examination.
14.4.4 All edges prepared for welding and all openings shall be magnetic particle examined in accordance with the applicable Code.
14.4.5 Forgings shall be examined on all surfaces, utilizing wet fluorescent magnetic particle method after final machining. All defects shall be removed and repaired by welding in accordance with SAES-W-010.
Exception:
Except for welding edges, liquid penetrant examination is acceptable as an alternative to magnetic particle examination.
14.5 Liquid Penetrant Examination
For non-Ferro magnetic materials, liquid penetrant examination shall be used for the following welds:
a) Pressure containing welds joints categories A, B, C and D per Table 1 of this specification.
b) Welds in vessel support (skirt, saddle, lug, and leg) c) Attachment welds to the pressure vessel
d) Areas where temporary attachments have been removed e) Arc strike areas
14.6 Welds Encroachment
Where the optimized fabrication layout and/ or process design requirements do not absolutely allow meeting the spacing requirement in paragraph 13.2.6.1 of
this specification, NDE per the following table shall be performed.
Case PWHT is required ( Note 1) PWHT is not required
1. Nozzle or manway without a reinforcing pad installed onto a butt weld in vessel wall
RT of butt weld in vessel for a length equal to three times the diameter of the opening with the center of the opening at mid-length.
Same as when PWHT is required.
2. Nozzle or manway with a reinforcing pad installed onto a butt weld in vessel wall
N/A
(See paragraph 8.5.2 of this specification)
RT of butt weld in vessel for a length equal to three times the diameter of the opening with the center of the opening at mid-length.
The butt weld shall be ground flush prior to installation of the pad.
3. Nozzle or manway, without a reinforcing pad, encroaching on a butt weld in vessel wall
RT of butt weld in vessel for a length equal to three times the diameter of the opening with the center of the opening at mid-length.
Same as when PWHT is required.
4. Reinforced nozzle or manway with the reinforcing pad encroaching on the butt weld in vessel wall
N/A
(See paragraph 8.5.2 of this specification)
RT of butt weld in vessel for a length equal to three times the diameter of the opening with the center of the opening at mid-length.
5. Reinforced nozzle or manway with penetration encroaching the butt weld and the reinforcing pad covering it
N/A
(See paragraph 8.5.2 of this specification)
RT of butt weld in vessel for a length equal to three times the diameter of the opening with the center of the opening at mid-length.
The butt weld shall be ground flush prior to installation of the pad.
6. Structural attachment, without a reinforcing pad, encroaching on a butt weld in vessel wall
RT of butt weld in vessel for a length equal to the projection of the attachment weld plus a minimum of 50 mm on either side.
Minimum length of the radiographed weld is 12 inches.
Same as when PWHT is required.
7. Reinforced structural attachment, with the reinforcing pad encroaching on a butt weld in vessel wall
RT of butt weld in vessel for a length equal to the projection of the reinforcing pad attachment weld plus a minimum of 50 mm on either side. Minimum length of the radiographed weld is 12 inches.
Same as when PWHT is required.
8. Structural attachment, without a reinforcing pad, covering a butt weld in vessel wall
N/A
(See prohibition in paragraph 13.2.6.3 of this specification)
RT of butt weld in vessel for a length equal to the projection of the reinforcing pad attachment weld plus a minimum of 50 mm on either side. Minimum length of the radiographed weld is 12 inches.
9. Reinforced structural attachment, with the reinforcing pad covering a butt weld in vessel wall
N/A
(See prohibition in paragraph 13.2.6.3 of this specification)
RT of butt weld in vessel for a length equal to the projection of the reinforcing pad attachment weld plus a minimum of 50 mm on either side. Minimum length of the radiographed weld is 12 inches. The butt weld shall be ground flush prior to installation of the pad.
10. Structural attachment (with or without reinforcing pads) encroaching:
a) Another structural attachment (with or without reinforcing pads)
b) Reinforced nozzle or manway c) Nozzle or manway without a
reinforcing pad
MP or LP on the entire outermost fillet weld of each attachment on the vessel side per paragraph 14.4 or 14.5, as applicable, after completion of all welds in all attachments.
Same as when PWHT is required.
Note 1: NDE for final acceptance of the vessel shall be performed after the final PWHT per paragraph 14.1.3 of this specification.
14.7 Hardness Testing
Weld hardness testing shall be in accordance with the requirements of SAES-W-010.