Leak-Proof FC Valve Seat for Petroleum | Thermal Spray Coating | High-Strength Alloy | China Suppliers & Factory
Product Description
The FC (Failed Close) automatic shut-off valve seat is a core sealing and vulnerable component of gate valves used in oil drilling, production, oil and gas gathering and transportation, downhole operations, and wellhead systems.
The product employs a professional fail-safe shut-off (FC) design. When sudden conditions occur in oilfield equipment, such as power outages, abnormal system pressure, or actuator malfunctions, the valve seat, in conjunction with the valve structure, automatically and quickly closes, locking the oil and gas medium passage. This fundamentally prevents safety accidents such as blowouts, medium leaks, and equipment malfunctions, strictly adhering to the safety standards for high-risk oilfield operations.
The valve seat uses high-strength alloy structural steel as its base material, precision-machined using CNC lathes and grinders to ensure assembly accuracy. The sealing surface undergoes a high-velocity oxygen fuel spraying (HVOF) tungsten carbide (WC) strengthening process, resulting in a coating with strong adhesion, high hardness, erosion resistance, and corrosion resistance. It can withstand harsh operating conditions such as sandy mud, high-pressure oil and gas, and corrosive media in oilfields for extended periods, significantly improving the sealing stability and service life of the gate valve. It is a core component of valve systems in onshore oilfields and offshore drilling platforms.
Product Specifications
| Type | FC Valve Seat |
| Nominal Diameter | 1-13/16"/ 2-1/16"/ 2-9/16"/ 3-1/16"/ 3-1/8"/ 4-1/16"/ 5-1/8"/ 6-5/8"/ 7-1/16"/ 9"/ 11"/ 13-5/8" (custom sizes available upon request) |
| Working Pressure | 2000psi(2K)/ 3000psi(3K)/ 5000psi(5K)/ 10000psi(10K)/ 15000psi(15K)/ 20000psi(20K) (Customized solutions are available for high-temperature working conditions.) |
| Media | Crude oil, natural gas, drilling mud, sand-containing oil and gas, corrosive oil and gas media |
| Material | High-strength alloy structural steel (42CrMo/40CrNiMo premium grade) |
| Working Temperature | -46℃ - +121℃ |
| Hardness | HRC75 |
| Bonding Strength | ≥70MPa |
| Porosity | <1% |
| Surface Treatment | Supersonic spraying of cobalt-bonded tungsten carbide (WC/Co) / cobalt-chromium-bonded tungsten carbide (WC/CoCr) / cobalt-chromium tungsten alloy (Stellite 20#/NiCr) / nickel-chromium-bonded chromium carbide (Cr₃C₂/NiCr) / nickel-based alloy (Ni60/Ni55) / nickel-based tungsten carbide (WC/Ni) |
| Coating Thickness | 0.03–0.5mm (Customizable) |
| Compatible Equipment | Oilfield gate valves, Christmas tree gate valves, drilling high-pressure valves |
| Pressure Rating | Suitable for high-pressure oilfield conditions (custom pressure ratings available) |
| Sealing Performance | Zero leakage under high pressure, suitable for stringent sealing requirements in oilfields |
| Application Areas | Onshore oilfields, offshore drilling platforms, oil and gas gathering and transmission pipelines, downhole equipment |
Product Features
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1. Fail-Safety Assurance
Employs FC (Failed Close) automatic shut-off design, quickly closing and locking in case of power failure or equipment malfunction to prevent oil and gas leaks, complying with oilfield safety operation regulations.
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2. Ultra-Wear-Resistant and Erosion-Resistant
The sealing surface features a tungsten carbide thermal spray coating with a hardness ≥ HRC75, strongly resisting high-speed erosion from sand-containing media, resulting in a service life far exceeding that of ordinary valve seats.
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3. High-Pressure Sealing Stability
Precision-machined sealing surfaces achieve high precision in smoothness and flatness, ensuring zero leakage and no pressure relief under high-pressure conditions, providing long-lasting and reliable sealing performance.
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4. Strong Corrosion and Impact Resistance
Double corrosion resistance of the substrate and coating, suitable for harsh conditions such as salt spray, acidic oil and gas, and mud; the high-strength substrate is impact-resistant, non-deformable, and crack-free.
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5. Precise and Universal Assembly
Standard structural dimensions perfectly match various oil gate valves, facilitating easy installation, smooth opening and closing without jamming, and requiring no equipment modification.
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6. Strong Customization and Adaptability
Supports customization of size, material, coating, and pressure rating to meet the specific needs of different oilfield equipment and operating conditions.
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7. Significant Cost Reduction and Efficiency Improvement
Ultra-long service life reduces replacement frequency, lowers equipment downtime and maintenance costs, and improves oilfield operation efficiency.
Product Packaging
Standard Export Packaging Specification
Outer Layer: Fumigation-free plywood box or heavy-duty carton.
Protection: The packaging system is designed to be impact-resistant, moisture barrier, and anti-corrosive, guaranteeing the integrity of the goods during maritime transit.
Outer Layer: Fumigation-free plywood box or heavy-duty carton.
Protection: The packaging system is designed to be impact-resistant, moisture barrier, and anti-corrosive, guaranteeing the integrity of the goods during maritime transit.
Product Transportation
Logistics & Delivery
- Maritime Transport
- Land & Rail (Surface Transport)
Frequently Asked Questions
Q
What does FC (Failed Close) mean in the context of this valve seat?
FC stands for "Failed Close," a fail-safe design principle that ensures the valve seat automatically closes and locks the oil and gas passage when the system loses power, experiences abnormal pressure, or the actuator malfunctions. This design prevents blowouts, leaks, and other safety incidents common in high-risk oilfield environments.
Q
What surface treatment is applied to the FC valve seat sealing surface?
The sealing surface is treated using High-Velocity Oxygen Fuel (HVOF) thermal spray technology, applying coatings such as tungsten carbide (WC/Co, WC/CoCr, WC/Ni), cobalt-chromium alloy (Stellite 20#/NiCr), chromium carbide (Cr₃C₂/NiCr), or nickel-based alloys (Ni60/Ni55). This results in a coating with hardness ≥ HRC75, strong adhesion, and excellent erosion and corrosion resistance.
Q
What pressure ratings are available for this FC valve seat?
The FC valve seat is available in a wide range of working pressures: 2000 psi (2K), 3000 psi (3K), 5000 psi (5K), 10,000 psi (10K), 15,000 psi (15K), and 20,000 psi (20K). Customized solutions for special high-temperature or ultra-high-pressure conditions are also available upon request.
Q
Can the FC valve seat be customized for specific oilfield equipment?
Yes. The FC valve seat supports full customization including nominal diameter, base material, coating type, coating thickness (0.03–0.5mm), and pressure rating. It is designed to be compatible with oilfield gate valves, Christmas tree gate valves, and drilling high-pressure valves, and can be tailored to meet the specific requirements of different operating environments.
Q
What are the typical application areas for this FC valve seat?
The FC valve seat is widely used in onshore oilfields, offshore drilling platforms, oil and gas gathering and transmission pipelines, and downhole equipment. It is suitable for media including crude oil, natural gas, drilling mud, sand-containing oil and gas, and corrosive oil and gas media, operating within a temperature range of -46°C to +121°C.
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How is the FC valve seat packaged for international export?
The product is packaged according to standard export specifications using fumigation-free plywood boxes or heavy-duty cartons. The packaging is engineered to be impact-resistant, moisture-proof, and anti-corrosive, ensuring the product arrives in perfect condition during maritime or land/rail transportation.















