Product Overview
Our wellhead flange is a core forged transition fitting for oil/gas well surface well control systems, used to connect casing head, tubing head, blowout preventers (BOP), lubricators, flowline manifolds and other wellhead assemblies. This complete assembly includes the flange body, high-strength stud bolt sets, and metal ring gaskets for sealing. The upper and lower flange faces feature evenly distributed bolt holes for rigid bolted clamping; the central through bore provides unobstructed flow passage for downhole tools, production fluid and treatment fluid. The red epoxy coating offers excellent corrosion resistance for outdoor rig environment, protecting base metal from rain, mud, salt spray erosion.
The flange body adopts monolithic alloy steel forging followed by heat treatment to achieve stable mechanical performance under high pressure; sealing grooves are precision machined to fit API metal ring gaskets, forming reliable metal-to-metal sealing to prevent well fluid leakage. Sour-grade material options comply with NACE MR0175 / ISO 15156 for H₂S, CO₂ corrosive wells. Widely used for new well completion, workover retrofit, adding lubricator/BOP stack, wellhead piping modification operations.
Core Features & Benefits
- Integral forged body eliminates hidden welding seam leakage risks, reliable for long-term high-pressure service
- Precision machined API RX/BX ring grooves, matched metal ring gaskets achieve robust metal-to-metal sealing
- Supplied as full assembly: flange body, alloy stud bolts, sealing rings, saves separate component procurement work
- Durable red epoxy outer coating improves outdoor corrosion resistance and visual inspection convenience
- Standard API flange dimensional compatibility, directly mates with mainstream wellheads, BOPs and adapters
- Multiple pressure classes (2000–15000 psi) and bore sizes for different casing/tubing specifications
- Sour service material variants available for high-sulfur corrosive well sites
- High-strength alloy studs provide stable preload, resist bolt loosening under pressure cycling & thermal fluctuation
- Custom bore size, bolt pattern and interface structure for special wellhead renovation projects
- Strict hydrostatic pressure testing conducted before factory delivery
Technical Specifications
| Model No. | API Pressure Rating | Nominal Bore | Ring Type | Standard Bolt Material | Temperature Range | Service Grade |
|---|---|---|---|---|---|---|
| WHF-4-3K | 3000 psi | 4" | RX | A193 B7 | -20°F~350°F | Standard |
| WHF-4-5K | 5000 psi | 4" | RX/BX | A193 B7 | -20°F~350°F | Standard |
| WHF-5-10K | 10000 psi | 5" | BX | A193 B7 | -20°F~350°F | Standard |
| WHF-4-5K-S | 5000 psi | 4" | RX/BX | A193 B7M | -20°F~350°F | Sour H2S |
| WHF-5-10K-S | 10000 psi | 5" | BX | A193 B7M | -20°F~350°F | Sour H2S |
Note: Custom bore, bolt layout, pressure rating and coating options are available upon request.
Typical Applications
- Transition connection between tubing head and blowout preventer stack
- Installation adapter for wireline / coiled tubing lubricators on existing wellheads
- Wellhead manifold branching, production flowline connection
- Sour well wellhead upgrading with NACE compliant flanges
- Workover rig wellhead retrofitting to adapt different size well control equipment
- Pressure testing interfaces for wellhead assemblies
- Casing spool extension for additional downhole intervention operations
Advantages Vs Split Welded Transition Connectors
- Monolithic forging avoids welding defect leakage points, greatly improves operational safety under high pressure
- Complete package (flange + bolts + gaskets) simplifies site stocking and assembly scheduling
- Factory pre-machined sealing grooves guarantee sealing performance, lower on-site assembly error risk
- Protective coating extends outdoor service life, reduces regular maintenance repaint workload
- API interchangeability enables direct replacement for mainstream wellhead products
- Sour grade configurations satisfy strict material requirements of sour gas field operators
FAQ
Can you manufacture non-standard bolt patterns or special inner bore sizes?
Yes, we produce custom machined flanges according to customer engineering drawings.What bolt & gasket options are provided for sour well use?
We supply B7M studs, sour-grade ring gaskets alongside NACE compliant flange bodies with full material test reports.Which API ring joint types can be processed?
RX, BX, R series ring groove machining is supported for common API flange standards.What is production lead time?
Standard API models ship within 7–12 working days; fully custom wellhead flanges take 20–30 working days including forging, machining and pressure testing.CTA
Get Custom Specification Sheet & Ex-Factory Bulk Price
We manufacture API certified wellhead flanges and matching fasteners, sealing components with full hydrostatic testing. Share required pressure rating, nominal bore and ring type, our engineering team will send detailed datasheet and quotation within 24 hours.
