The Oil Well Christmas Tree Valve Body is a pressure-containing component used in oil and gas wellhead systems to control the flow of hydrocarbons from the well. Named for its tree-like configuration of Valves, spools, and fittings, the Christmas tree operates under extreme pressures (up to 10,000 PSI), corrosive H2S/CO2 environments, and wide temperature ranges (-50°C to +120°C).
Ningbo Ruican manufactures this valve body using precision Investment Casting of AISI 4130 low-alloy steel, followed by multi-axis CNC MACHINING of flange faces, threaded connections, and internal flow passages. All components are manufactured to API 6A specification and NACE MR0175 sulfide stress cracking resistance requirements.
Material Specifications
| Parameter | Specification |
|---|---|
| Material | AISI 4130 (25CrMo4) low-alloy steel |
| Tensile Strength | ≥ 655 MPa |
| Yield Strength | ≥ 517 MPa |
| Elongation | ≥ 17% |
| Hardness | ≤ 22 HRC (NACE MR0175 compliant) |
| Heat Treatment | Normalized + Tempered (Q&T) |
| Impact Toughness | ≥ 20 J (at -29°C, Charpy V-notch) |
Casting Specifications
| Parameter | Specification |
|---|---|
| Casting Process | Silica sol investment casting |
| Dimensional Tolerance | ISO 8062 CT5–CT6 |
| Surface Roughness | Ra 3.2–6.3 μm (as-cast); Ra 1.6 μm (machined) |
| Weight Range | 15–200 kg |
| Wall Thickness | 10–50 mm |
| Pressure Rating | 5,000–10,000 PSI (API 6A PSL 2–3) |
CNC Machining Parameters
| Parameter | Specification |
|---|---|
| Flange Face Flatness | ≤ 0.02 mm (API 6A Ring Groove) |
| Bore Tolerance | ±0.03 mm |
| Thread Accuracy | API Spec 5B (API REG or buttress) |
| Surface Finish (flange) | Ra 1.6 μm (machined) |
| Ring Groove | Rex API 6A Type RX/RX-BX, ±0.025 mm |
| Concentricity | ≤ 0.05 mm |
Quality Control
- 100% dimensional inspection with CMM (including ring groove verification)
- Magnetic particle inspection (MPI) per ASTM E709
- Ultrasonic testing per ASTM E2375 (Level 2 minimum)
- Hardness testing (NACE MR0175 compliance — ≤22 HRC)
- Hydrostatic body test at 1.5× rated working pressure
- Material certificate per EN 10204 3.1 with full chemistry
- API 6A PR2 (Performance Rating 2) testing available
Applications
- Onshore oil and gas wellhead systems
- Offshore platform Christmas tree assemblies
- Subsea wellhead systems
- Gas injection and production wells
- High-pressure/high-temperature (HPHT) wells
