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J-VALVES
Structural Features
Low Alloy Steel F11 Material: The valve body is fabricated from ASTM A182 F11 (1.25Cr‑0.5Mo) or ASTM A217 WC6 cast low alloy steel. The chromium‑molybdenum alloy delivers excellent oxidation and sulfidation resistance, outstanding hydrogen corrosion and hydrogen embrittlement resistance, as well as favorable weldability and heat treatability.
Y‑Type Body Design: The valve body features a 45° inclined flow passage, reducing flow resistance coefficient by 60%–70% and significantly lowering pressure drop. Fluid direction changes gently, minimizing turbulence and cavitation. The disc stroke provides a more linear flow characteristic, improving control accuracy. It is suitable for high differential pressure and large flow rate conditions, reducing pumping energy consumption.
Outside Screw & Yoke (OS&Y) Stem Design: Stem threads are located outside the valve body, fully isolated from the medium to avoid corrosion and contamination. The yoke supports the stem nut for stable operating torque, enabling clear visual indication of valve open/closed position, in compliance with API 602.
Conical or Parabolic Disc: Precision‑machined conical or parabolic sealing surfaces ensure reliable sealing and precise flow regulation. Equal percentage or linear flow characteristics make it ideal for throttling applications.
Flanged or Welded Connections: Available in flanged (RF/RTJ, ASME B16.5) or butt weld (BW, ASME B16.25) ends to meet various installation requirements.
Pressure‑Seal Bonnet (High‑Pressure Version): Pressure‑energized self‑seal bonnet is adopted for Class 900 and above. Sealing reliability improves with increasing medium pressure, suitable for ultra‑high pressure services.
Fire‑Safe Design: Complies with API 607. Metal‑to‑metal sealing maintains integrity under fire conditions to prevent media leakage.
Blowout‑Proof Stem: Top‑entry blowout‑proof stem with shaft shoulder and retaining ring ensures the stem cannot be ejected under abnormal internal pressure, enhancing operational safety.
Back Seat Design: When fully open, a metal seal forms between the stem and bonnet, allowing online packing replacement without system depressurization.
Flexible Graphite Packing: High‑purity flexible graphite packing offers a wide temperature range (-200°C to +600°C), excellent self‑lubrication and sealing performance. A packing lubrication fitting can be provided for emergency sealing.
Specifications
Size Range: 2″ to 24″ (DN50 to DN600)
Pressure Class: Class 600 to Class 2500 (PN100 to PN420)
Temperature Range: -29°C to +425°C
Body/Bonnet: ASTM A182 F11, A217 WC6; optional F22/WC9 (2.25Cr‑1Mo, up to +593°C), F91/C12A (9Cr‑1Mo‑V, up to +650°C)
Disc/Seat: F11 with STL6 overlay, F22 with STL6 overlay, F316 with STL6 overlay, solid STL6
Stem: F6a, F316, 17‑4PH, Inconel 718, XM‑19 (Nitronic 50)
Sealing Surfaces: STL6 (Stellite 6), STL21, nickel‑base alloy, tungsten carbide
Packing: Flexible graphite, graphite reinforced with nickel wire, PTFE (low‑temperature type)
Gaskets: Flexible graphite spiral wound gasket (304/316), metal ring joint gasket (RTJ), pressure‑energized self‑seal ring (high‑pressure type)
End Connections: Flanged (RF/RTJ, ASME B16.5), Butt Weld (BW, ASME B16.25), Socket Weld (SW, ASME B16.11)
Operation: Manual (handwheel / impact handwheel), gearbox (bevel / worm gear for large sizes), pneumatic (linear stroke), electric (multi‑turn), hydraulic
Design Standard: API 602, ASME B16.34
Test Standard: API 598
Applications
Thermal Power Systems: Used for regulation and shutoff of high‑temperature and high‑pressure steam in main steam, reheat steam, feedwater and extraction systems, capable of withstanding 538°C steam for subcritical and supercritical units.
Petrochemical & Refining Industry: Applied for flow control and reliable isolation of high‑temperature oil, gas and steam in fluid catalytic cracking, hydrocracking, reforming, coking and other units.
Coal Chemical Industry: Used for regulation and control of high‑temperature and high‑pressure syngas, water gas and coal‑water slurry in coal gasification, coal‑to‑liquid, coal‑to‑olefins plants.
Chemical Synthesis Systems: Provides precise control of process gas, recycle gas and steam in ammonia, methanol, urea and other synthesis plants.
Metallurgical Industry: Serves blast furnace gas, converter gas, coke oven gas systems, as well as high‑temperature gas regulation and isolation in hot blast stoves and heating furnaces.
Gas‑Steam Combined Cycle: Used in high‑temperature and high‑pressure systems of gas turbines, heat recovery steam generators and steam turbines in combined cycle power plants.
General Industrial Service: Applied for flow regulation and reliable isolation of high‑temperature steam, hot oil and high‑temperature gas, acting as critical control equipment in high‑temperature and high‑pressure pipelines.
Advantages & Value
Low Flow Resistance Y‑Type Structure: The 45° inclined passage drastically reduces pressure drop and energy consumption, cutting pumping power by 20%–30% compared with conventional globe valves, delivering significant long‑term energy savings.
Excellent High‑Temperature Performance: F11 Cr‑Mo low alloy steel features superior high‑temperature strength and creep resistance, enabling stable long‑term operation at 538°C for the most severe high‑temperature and high‑pressure services.
Precise Control Characteristics: The conical/parabolic disc combined with Y‑type flow passage provides excellent linearity of flow characteristics and high regulation accuracy to meet precise process control requirements.
Hydrogen Corrosion Resistance: Cr‑Mo alloy offers excellent resistance to hydrogen corrosion and hydrogen embrittlement, suitable for hydrogen‑processing services such as hydrotreating and ammonia synthesis.
Safe & Reliable Operation: OS&Y design provides clear visual stem position indication; blowout‑proof stem and back seat design ensure safe operation and maintenance.
Convenient Online Maintenance: Back seat design permits in‑service packing replacement; flanged or welded connections facilitate installation and overhaul.
Easy Automation Integration: Direct mounting of linear pneumatic or electric actuators with positioners enables 4–20mA precise control, with seamless integration into DCS systems.
Wide Application Versatility: Multiple Cr‑Mo steel materials (F11/F22/F91), sealing face materials and end connections are available, covering services from ambient temperature up to 650°C ultra‑high temperature.
International Standard Compliance: Designed and manufactured strictly in accordance with API 602, ASME, EN, ISO and other international standards to meet global project procurement requirements. Complete material certifications (EN 10204 3.1/3.2), high‑temperature tensile test reports, metallographic analysis reports and NACE compliance certificates are provided.
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