Inspection Outline for a Certain Pressure Vessel Equipment

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1 Material Control
Serial Number | Inspection Item | Code | Quality Indicator | Inspection Method | Remarks
1.1 Cylinder A1: The steel plates used for the cylinder and end caps are of grade Q345R (normalized) + S30403 (solution-treated), in compliance with the requirements of NB/T 47002.1-2019 “Explosively Welded Composite Plates for Pressure Vessels” – Grade B2. Re-inspection shall be carried out in accordance with the additional technical requirements specified in the drawings.
2. Flanges and forgings must meet the requirements of NB/T 47008-2017 “Carbon Steel and Alloy Steel Forgings for Pressure Equipment”.
3. The steel used for pipes is 0Cr18Ni9; it must comply with the requirements of GB/T 14976-2012 “Stainless Steel Seamless Pipes for Fluid Conveyance”. Physical inspection as well as construction-related documentation shall be verified.
1.2 End Caps
1.3 Nozzles
1.4 Flanges
1.5 Forgings
1.6 Welding Materials (electrodes, wires, fluxes)
A. Welding materials used for welding:
a. Must comply with the provisions of JB4747-2007.
b. Must be baked as specified before use.
c. The grade and specifications of the welding materials must meet the requirements of the welding process.
d. Records of material receipt, welding procedures, and material certificates must be consistent and traceable. Documentation shall be verified.

Table 2 Welding
Serial Number | Inspection Item | Code | Quality Indicator | Inspection Method | Remarks
2.1 Welder Qualifications
A. Welders who perform welding on equipment must pass the examinations specified in the regulations related to pressure vessels, as well as those outlined in the “Rules for the Examination and Management of Welders for Boilers, Pressure Vessels, and Pressure Pipelines”, and must hold valid certificates. Verify the welder’s qualification certificates for the welding tasks. 2.2 Welding Procedure Qualification: The welding joints to be qualified shall undergo welding procedure qualification in accordance with JB4708-2000, and a complete welding procedure qualification report must be available. Verify the welding procedure qualification report. 2.3 Internal quality of welds: a. The proportion of non-destructive testing for butt welds (including extended testing), as well as the acceptance criteria, shall comply with the specifications and JB/T4730-2005. b. The procedures for repairing welds in the same area, as well as the repair methods and records, shall meet the standard requirements. a. Verify the non-destructive testing reports and inspection records. b. Verify the repair documentation. 2.4 The excess height of butt welds shall comply with GB150-1998; the requirements regarding excess height are specified by the relevant standards. Weld inspection device. 2.5 Width of butt welds: a. The difference in width between different sections of the same weld shall not exceed 4 mm. b. For welds of the same type, the difference in width shall not exceed 6 mm. Weld inspection device. 2.6 Quality of fillet welds: a. The dimensions of the fillet welds shall comply with GB150-2011 or the specifications given in the drawings. b. The transition from the weld to the base material shall be smooth, as determined by visual inspection. Weld inspection device. 2.7 Visual quality of welds: The weld surface shall be free of cracks, pores, slag inclusions, and spatter ； If necessary, add surface inspection visually; 2.8 The weld undercutting shall meet the requirements of GB150-2011, the design specifications, and those regarding undercutting. Visual inspection, weld detector; steel tape measure, 2.9. Welder’s mark Aa: The welds of the main stressed components shall have a clear welder’s mark in the specified location. b. When marking is not permitted. A diagram showing the distribution of welder’s stamps should be prepared based on the construction records, with full traceability. a. Verify the actual items to ensure they match the records. b. Check the welders’ qualifications. 2.10 Non-destructive testing documents: a. The non-destructive testing reports must comply with JB/T4730-2005 or the requirements specified in the drawings. b. There must be a diagram indicating the locations where non-destructive testing was performed. c. The markings on the actual items must be clear and accurate. d. When stamping is not allowed, there must be traceable documentation. a. Verify the non-destructive testing documents. b. Verify the actual items. 2.11 Welding records: The welding procedures recorded must comply with the requirements of the welding procedure specifications; the records must be complete and accurate. Verify the records. Table 3: Assembly – Serial number, inspection items, item codes, quality criteria, inspection methods, and remarks. 3.1 Inspection of cylinder cutting: Comply with the requirements specified in the drawings; use a steel tape measure and a straightedge. 3.2 Inspection of cylinder groove preparation: Must meet the process requirements specified in the drawings; use visual inspection and a weld inspection gauge. 3.3 Misalignment of longitudinal welds on the cylinder (b): For Class A and B welds, the misalignment must comply with the provisions in Table 10-1 of GB150-2011; use a weld inspection gauge and a straightedge. 3.4 Welding (including surfacing): Welding must be carried out in accordance with the welding procedure specifications; the records must be complete and accurate. Verify the records. 3.5 Non-destructive testing: a. The non-destructive testing reports must comply with JB/T4730.1–6-2005 or the requirements specified in the drawings. b. There must be a diagram indicating the locations where non-destructive testing was performed. c. The markings on the actual items must be clear and accurate. d. When stamping is not allowed, there must be traceable documentation. a. Verify the non-destructive testing documents. b. Verify the actual items. 3.6 Difference between maximum and minimum diameters on the same cross-section of the cylinder: Must comply with the provisions in GB150-2011, Article 10.2.4.10; use a laser distance meter. 3.7 Allowable tolerance for the inner diameter of the cylinder: The deviation should be within 0–+10, as determined by using a tape measure. 3.8 Sharp corners formed at longitudinal welds (E): Must comply with GB150-2011, where E ≤ δ/10 + 2, and also ≤ 5 mm. Testing is carried out using a gauge with a length of 1/6 DN, with a minimum length of 300 mm. 3.9 The weld arrangement meets the requirements specified in GB150-2011 and the design drawings; visual inspection is performed using a steel tape measure. 3.10 For circumferential welds, the misalignment amount (b) must comply with the provisions in Table 10-1 of Article 10.2.4.1 of GB150-2011. 3.11 The corners formed at circumferential welds (E) must satisfy the condition E≤δ/10+2, with a maximum value of 5 mm. Special inspection straightedge, with a length of not less than 300 mm. 3.12 The straightness of the cylinder body, ΔL, shall comply with GB150-2011: ≤1‰ of L (not more than 4.5 mm when L ≤ 6000, and not more than 8 mm when L > 6000). Steel wire straightedge. 3.13 Welding (including surfacing welding): Welding shall be carried out in accordance with the specified welding procedures; the records of welding shall meet the requirements of these procedures, and such records must be thoroughly checked. 3.14 Non-destructive testing: a. The non-destructive testing reports shall conform to JB/T4730.1–6-2005 or the requirements specified in the drawings. b. There shall be diagrams showing the locations where non-destructive testing was performed. c. The markings on the actual components shall be clear and accurate. d. When stamping marks are not allowed, there shall be traceable documentation available. a. Check the non-destructive testing documents. b. Inspect the actual components. 3.15 The tolerances for the orientation of pipe ends, their elevation, and their dimensions shall comply with the requirements specified in the drawings and HG20584-2011 standards ； Visual inspection with a steel tape measure and straight edge: 3.16 Dimensions of the skirt seat position; 3.17 Mechanical damage on the container’s surface and degree of grinding. The slope of the grinding area should be at least 1:3, while the grinding depth shall not exceed 5% of the thickness of the steel plate in that area, nor more than 2 mm; otherwise, welding repairs must be carried out. Visual inspection using an ultrasonic thickness gauge: 3.18 The piping and flange components, as well as the cylinder (head), shall be assembled in accordance with GB150-2011 and the requirements specified in the drawings; visual inspection with a ruler is required. 3.19 The alignment of the bolt holes on the flanges with the centerline of the equipment’s main shaft shall comply with GB150-2011 and the requirements in the drawings; visual inspection with a ruler is necessary. 3.20 The flange surface shall be perpendicular to the piping or cylinder, in compliance with GB150-2011 and the requirements outlined in the drawings; a flexible rule is used for this check. 3.21 Welding (including surfacing welding) shall be carried out in accordance with the specified welding procedures; the records of the welding process must meet the requirements of the relevant welding procedures, and these records shall be thoroughly checked. 3.22 The visual quality of the welds: The weld surface shall not have any cracks, pores, slag inclusions, or spatter ； Visually inspect; if necessary, perform surface inspection.
3.23 Quality of fillet welds
a. The weld size shall comply with GB151-2011 or the requirements specified in the drawings.
b. The transition between the weld and the base metal should be smooth. Visually inspect using a weld inspector.
3.24 Assembly of head components with the shell, and assembly of skirt components with the head; installation of accessories shall comply with GB150-2011. Visually inspect using a straightedge.
3.25 Misalignment at circumferential weld joints (b): The misalignment for Class A and Class B welds shall conform to the provisions in Table 10-1, Section 10.2.4.1 of GB150-2011. Visually inspect using a weld inspector.
3.26 Welding (including surfacing): Welding shall be carried out in accordance with the welding procedure. The welding parameters recorded must meet the requirements of the welding procedure specification; records must be complete and accurate. Verify these records.
3.27 Post-weld inspection
a. Non-destructive testing reports must comply with JB/T4730-2005 or the requirements specified in the drawings.
b. There must be a diagram indicating locations where non-destructive testing was performed (layout drawing).
c. Markings on the actual product must be clear and accurately positioned.
d. When stamping markings is not permitted, there must be traceable documentation available.
a. Verify non-destructive testing documentation.
b. Inspect the actual product.
3.28 Assembly of skirt components with the head; installation of accessories shall comply with GB150-2011. Visually inspect using a straightedge.
3.29 Welding: Welding shall be carried out in accordance with the welding procedure. The welding parameters recorded must meet the requirements of the welding procedure specification; records must be complete and accurate. Verify these records.
3.30 Post-weld inspection
a. Non-destructive testing reports must comply with JB/T4730-2005 or the requirements specified in the drawings.
b. There must be a diagram indicating locations where non-destructive testing was performed (layout drawing).
c. Markings on the actual product must be clear and accurately positioned.
d. When stamping markings is not permitted, there must be traceable documentation available.
a. Verify non-destructive testing documentation.
b. Inspect the actual product.
3.31 Appearance, geometric dimensions, and orientation must conform to the drawings. Visually inspect and verify.

Table 4: Outsourced head forming
| No. | Inspection item | Item code | Quality criteria | Inspection method | Remarks |
|-----|-----------------|-----------|------------------|-------------------|---------|
| 4.1 | Cutting of head material | | Must meet drawing requirements (considering thickness reduction) | Steel tape measure, straightedge | |
| 4.2 | Groove processing | | Check for cracks, delamination, oil contamination, oxides, metal chips, and other harmful impurities | Visually inspect; use a weld inspection gauge | |
| 4.3 | Misalignment at head seams (b) | | Misalignment for Class A and Class B welds must comply with Table 10-1, Section 10.2.4.1 of GB150-2011 | Weld inspection gauge, straightedge | |
| 4.4 | Welding (including surfacing) | | Welding must be carried out in accordance with the welding procedure. Recorded welding parameters must meet the requirements of the welding procedure specification; records must be complete and accurate | Verify records | |
| 4.5 | Grinding of welds prior to outsourced forming | | Welds must be ground so that they are flush with the base metal | | |
| 4.6 | Tolerances for outer circumference and inner diameter | | Must comply with provisions in Sections 6.3.4.1 and 6.3.4.2 of JB/T4746-2002 | Tape measure, steel tape measure | |
| 4.7 | Shape deviation | | Must comply with provisions in JB/T4746-2002 | Template, steel tape measure | |
| 4.8 | Maximum gap | | Protrusions ≤ 1.25% of Di; recesses ≤ 0.625% of Di | Template | |
| 4.9 | Measured thickness of head | A | Must be no less than the nominal thickness minus any negative deviation of the steel plate | Ultrasonic thickness gauge | |
| 4.10 | Roundness tolerance | | Must be ≤ 0.5% of Di and not exceed 25 mm | Steel tape measure, straightedge | |
| 4.11 | Non-destructive testing | a. Non-destructive testing reports must comply with JB/T4730-2005 or the requirements specified in the drawings.<br>b. There must be a diagram indicating locations where non-destructive testing was performed (layout drawing).<br>c. Markings on the actual product must be clear and accurately positioned.<br>d. When stamping markings is not permitted, there must be traceable documentation available. | a. Verify non-destructive testing documentation.<br>b. Inspect the actual product. | |

Table 5: Machining
| No. | Inspection item | Item code | Quality criteria | Inspection method | Remarks |
|-----|-----------------|-----------|------------------|-------------------|---------|
| 5.1 | Thickness of nozzle flanges | B | Must meet GB/T1804 and drawing requirements | Calipers | |
| 5.2 | Thickness and height of nozzles | | Must meet GB/T1804 and drawing requirements | Calipers | |
| 5.3 | Thickness of manhole flanges | | Must meet GB/T1804 and drawing requirements | Calipers | |
| 5.4 | Thickness and height of manhole nozzles | | Must meet GB/T1804 and drawing requirements | Calipers | |
| 5.5 | Thickness of manhole covers | | Must meet GB/T1804 and drawing requirements | Calipers | |

Table 6: Performance tests and accessories
| No. | Inspection item | Item code | Quality criteria | Inspection method | Remarks |
|-----|-----------------|-----------|------------------|-------------------|---------|
| 6.1 | Pressure test | A | Must comply with GB150-2011 and drawing requirements; follow procedures and requirements outlined in GB150-1998; record results | | |
| 6.2 | Pressure gauges | | Verify calibration date, class, range, and dial diameter | | |
| 6.3 | Water quality analysis | B | Cl⁻ content must be ≤ 25 mg/l | | |
| 6.4 | Non-destructive testing | a. Non-destructive testing reports must comply with JB/T4730-2005 or the requirements specified in the drawings.<br>b. There must be a diagram indicating locations where non-destructive testing was performed (layout drawing).<br>c. Markings on the actual product must be clear and accurately positioned.<br>d. When stamping markings is not permitted, there must be traceable documentation available. | a. Verify non-destructive testing documentation.<br>b. Inspect the actual product. | |
| 6.5 | Penetrant testing | HG20584-2011 | Follow procedures and requirements outlined in Method C, Appendix A of HG20584-1998; record results | | |
| 6.6 | Purchased components | B | Must be accompanied by a complete quality certificate issued by the manufacturer | | |
| 6.7 | Outsourced components | | Must be accompanied by complete documentation verifying their manufacturing quality | | |

Table 7: Painting, packaging, and shipping documents
| No. | Inspection item | Item code | Quality criteria | Inspection method | Remarks |
|-----|-----------------|-----------|------------------|-------------------|---------|
| 7.1 | Cleanliness inside the vessel | B | No standing water or residual debris | Visually inspect | |
| 7.2 | Rust removal and painting | | Surface must be smooth, with uniform color; no runs or drips; appearance must be aesthetically pleasing; must comply with JB/T4711-2003 | Visually inspect | |
| 7.3 | Packaging | | Must comply with requirements outlined in JB/T4711-2003 | | | Visually, 7.4: No blue spots after pickling and passivation is considered acceptable. For blue spot inspection, visually, 7.5: The location and content of the nameplate must conform to the drawings and GB150-2011 standards. Visually, 7.6: The delivery documents must include a complete product quality certificate whose contents comply with G150-2011 and the requirements of the drawings. Check