Engineered for the most critical isolation applications in supercritical and ultra-supercritical power generation, the API 600 Electrically Actuated Integral Forged Gate Valve with Bypass represents the ultimate solution for high-temperature and high-pressure steam systems.
Unlike conventional cast steel valves, this valve features an integral forged body, eliminating casting defects and providing superior structural integrity under extreme thermal cycling. Designed specifically for power stations, the integrated bypass valve effectively balances upstream and downstream pressure before the main valve opens. This crucial feature significantly reduces the operating torque required by the electric actuator, prevents severe erosion of the main seating surfaces, and ensures smooth, safe operation in high-pressure environments.
Key Features & Benefits
• Integral Forged Steel Construction: Manufactured from a single piece of high-grade forged steel (ASTM A105 / F22 / F91). The continuous grain flow provides unmatched tensile strength, fatigue resistance, and leak-tight reliability in high-pressure steam service.
• Integrated Bypass Valve System: Features a precision-engineered bypass globe valve built directly into the main valve body. It equalizes pressure across the main gate prior to opening, protecting the electric actuator from overload and extending the valve's service life.
• Smart Electric Actuation: Compatible with multi-turn electric actuators featuring smart positioning, torque protection, and remote DCS/PLC integration. Ideal for automated, unattended power plant operations.
• Advanced Pressure Seal Bonnet: Utilizes a self-energizing pressure seal design. As internal steam pressure increases, the sealing force increases proportionally, ensuring zero leakage even during rapid startup and shutdown transients.
• High-Temperature Hard-Faced Trim: Seat rings and wedge seating surfaces are overlaid with Stellite 6 (Co-Cr-W alloy) to resist severe erosion, corrosion, and galling in high-temperature steam flows up to 600°C.
Technical Specifications
Parameter | Specification |
Valve Type | Integral Forged Gate Valve with Bypass |
Design Standard | API 600, ASME B16.34 |
Body Material | ASTM A105, A182 F22, A182 F91 (Forged Steel) |
End Connection | Butt Weld (BW) per ASME B16.25 |
Pressure Rating | Class 900, 1500, 2500, 4500 |
Size Range | 4" to 24" (DN100 - DN600) |
Temperature Range | -29°C to +600°C (Customizable up to 650°C) |
Actuation | Multi-turn Electric Actuator (Ex-proof / IP68) |
Testing & Inspection | API 598, NACE MR0175 (Sour Service Available) |
Applications
This high-performance forged gate valve is widely deployed in:
• Thermal Power Plants: Main steam isolation, hot/cold reheat lines, and high-pressure feedwater systems.
• Supercritical/ Ultra-Supercritical Units: High-temperature and high-pressure steam piping networks.
• Nuclear Power Facilities: Non-nuclear auxiliary steam and water isolation.
• Heavy Industrial Boilers: High-pressure steam generation and distribution systems.
FAQ Section
Q: Why is a bypass valve necessary for high-pressure electric gate valves?
A: In high-pressure steam systems, the differential pressure across a closed gate valve can be massive. Opening the main valve directly requires enormous torque, which can overload the electric actuator and cause severe erosion to the seating surfaces. The bypass valve equalizes the pressure first, allowing the main valve to open smoothly and safely with minimal torque.
Q: What are the advantages of an integral forged body over a cast body?
A: Integral forged valves are machined from a single solid block of steel, which aligns the grain structure and eliminates porosity, shrinkage, and inclusions common in castings. This results in superior mechanical strength, better resistance to thermal fatigue, and higher safety margins in extreme high-temperature power station applications.
Q: Can the electric actuator be integrated with our plant's DCS system?
A: Yes. We supply valves with premium multi-turn electric actuators that support 4-20mA feedback, Modbus/Profibus communication, and remote limit/torque monitoring, ensuring seamless integration into modern power plant Distributed Control Systems (DCS).
