Project Scope
This pressure pipeline subcontracting involves 12 hot tapping operations, including:
- 6 high-temperature (300°C) thermal oil tappings
- 2 non-standard natural gas pipeline tappings (D717 & D660, high-grade thick-wall)
- 4 vent line tappings
Key Technical Specifications:
| Pipeline | Dimensions | Material | Design Pressure | Operating Pressure | Special Requirements |
|---|---|---|---|---|---|
| Gas Main (D717) | 717.4×19.1mm | X60 | Class 600 | 6.0-7.0 MPa | Pigging compatible |
| Gas Main (D660) | 660×30mm | L415Q | Class 600 | 6.0-7.0 MPa | Thick-wall welding |
Critical Components:
- Branch connections: Four-way tees with pig barrier screens
- Protection plates: 50mm wall thickness design
Technical Challenges:
✅ Thick-wall welding procedures (AWS D1.1 compliant)
✅ High-pressure hot tapping (6-7MPa live lines)
✅ Non-standard pipe adaptations (D717/D660 configurations)
