1. Main Technical Parameters
The 2 in 105 MPa Swivel Joint is suitable for oil and gas wellheads, fracturing and related high-pressure fluid transmission systems, and may be used for pipeline connection and direction change under high-pressure service. The product technical data focuses on pressure-bearing performance, connection reliability, material performance and NDT quality.
| Item | Technical Information | Remarks |
|---|---|---|
| Product name | Swivel Joint | High-pressure pipeline connector |
| Model and specification | 2 in, 105 MPa | Model corresponding to historical inspection data |
| Main reference standards | API Spec 6A; SY/T 5127-2002 | Used together with the 2 in 105 MPa product technical documents |
| Hydrostatic strength test | 155.2 MPa | Two-stage pressure holding; no visible leakage |
| Hydrostatic sealing test | 105 MPa | Both ends tested separately; no visible leakage |
| Connection thread | 4.125-3-Acme-2G | Go/no-go gauge inspection passed |
| Elbow connector material | 20CrNiMoA | Alloy structural steel |
| Reducer connector material | 35CrMo | Alloy structural steel |
| Main inspection | Ultrasonic testing; magnetic particle testing | Used to confirm internal and surface defect control |
2. Inspection Basis and Quality Conclusion
Relevant historical inspection data shows that the 2 in 105 MPa Swivel Joint was inspected according to API Spec 6A, SY/T 5127-2002 and the 2 in 105 MPa Swivel Joint product technical documents.
The inspection scope covered hydrostatic strength, hydrostatic sealing, connection thread, material chemical composition, mechanical properties after heat treatment, hardness, ultrasonic testing, magnetic particle testing, appearance, marking and accompanying documents. The historical inspection conclusion was that all inspected items met the applicable standard requirements.
3. Pressure-Bearing and Sealing Performance
Hydrostatic strength test
The test pressure was raised from zero to 155.2 MPa and held for 3 minutes in the first stage. After depressurization, the pressure was raised again to 155.2 MPa and held for 15 minutes. No visible leakage was found during the test, and the hydrostatic strength inspection result was qualified.
Hydrostatic sealing test
Hydrostatic sealing tests were carried out separately on the left and right ends of the Swivel Joint. After the pressure was raised to 105 MPa and held for 3 minutes, it was raised again to 105 MPa and held twice for 15 minutes. No visible leakage was found in any pressure-holding stage, and the sealing performance met the requirements.
4. Connection Thread and Dimensional Accuracy
The connection thread specification is 4.125-3-Acme-2G. Dimensional accuracy was checked with go/no-go gauges. During the actual inspection, the no-go gauge entered by approximately 1/4 turn, and the result met the technical requirements.
5. Materials and Mechanical Properties
Elbow connector: 20CrNiMoA
The elbow connector is made from 20CrNiMoA alloy structural steel. Chemical composition test results from the historical inspection data are as follows:
| Element | Test Value | Element | Test Value |
|---|---|---|---|
| C | 0.21% | Si | 0.25% |
| Mn | 0.83% | Mo | 0.23% |
| Cr | 0.64% | Ni | 0.59% |
| S | 0.008% | P | 0.017% |
Mechanical property test results after heat treatment of the elbow connector are as follows:
| Inspection Item | Technical Requirement | Test Result |
|---|---|---|
| Tensile strength Rm | ≥655 MPa | 710 MPa |
| Yield strength Rp0.2 | ≥517 MPa | 570 MPa |
| Elongation A | ≥15% | 16% |
| Reduction of area | ≥20% | 22% |
| Impact absorbed energy Akv (-46°C) | ≥27 J | 30 J |
| Heat-treated hardness | 229-260 HB | 251 HB |
Reducer connector: 35CrMo
The reducer connector is made from 35CrMo alloy structural steel. Chemical composition test results from the historical inspection data are as follows:
| Element | Test Value | Element | Test Value |
|---|---|---|---|
| C | 0.33% | Si | 0.27% |
| Mn | 0.61% | Mo | 0.19% |
| Cr | 1.02% | S | 0.005% |
| P | 0.018% |
Mechanical property test results after heat treatment of the reducer connector are as follows:
| Inspection Item | Technical Requirement | Test Result |
|---|---|---|
| Tensile strength Rm | ≥655 MPa | 685 MPa |
| Yield strength Rp0.2 | ≥517 MPa | 545 MPa |
| Elongation A | ≥15% | 17% |
| Reduction of area | ≥20% | 23% |
| Impact absorbed energy Akv (-46°C) | ≥27 J | 36 J |
| Heat-treated hardness | 240-280 HB | 259 HB |
6. Non-Destructive Testing
Ultrasonic testing
Both the elbow connector and the reducer connector were subjected to ultrasonic testing. The inspection results met the applicable acceptance requirements, and no defect indications exceeding the specified reference level were found.
Magnetic particle testing
Both the elbow connector and the reducer connector were subjected to magnetic particle testing to inspect key surfaces and related areas for defects. The inspection results met the applicable acceptance requirements.
7. Appearance, Coating and Product Marking
Exposed surfaces are required to be smooth, and transition areas are required to be rounded. The coating shall be bright and uniform, without tackiness, cracking, peeling, wrinkling, bubbling, stains, runs, scratches or other defects that affect appearance and protective performance. The historical inspection result was compliant.
Product marking shall include necessary performance and manufacturing information, such as performance level, product specification level, rated working pressure, temperature class, material class, end connection thread specification, manufacturing date and manufacturer name or mark. The relevant inspection results were compliant.
8. Accompanying Technical Documents
The accompanying technical documents shall be complete, with necessary moisture-proof and anti-corrosion measures taken to meet transportation, storage and field-use requirements. Historical inspection results show that the accompanying document items met the applicable requirements.