Specification

DN100 Class 300 Forged Steel RF Metal Seal Trunnion Mounted Ball Valve

I. Product Overview

TIANYU API 6D forged steel flanged RF metal seal trunnion mounted ball valve is a high-performance flow control device engineered for harsh industrial environments. Built with forged steel for structural integrity and metal-to-metal sealing for durability, it features a trunnion-mounted ball design to handle high pressure and abrasive media. Compliant with international standards, it delivers reliable shut-off, low operating torque, and long service life in oil, gas, petrochemical, and power systems, making it a critical component for critical pipeline shut-off and regulation.

II. Key Attribute Parameters

Size Range: 2″-48″ (DN50-DN1200), covering small to large-diameter pipelines to meet diverse industrial flow requirements from equipment interfaces to main transmission networks.
Pressure Rating: ANSI CLASS 150-2500 (PN16-PN420), with Class 300 (5.0MPa) as a common specification, suitable for high-pressure systems like oil pipelines and process loops.
Temperature Range: -46℃-121℃, with material upgrades enabling operation in cryogenic (-196℃) or high-temperature (450℃) environments for specialized applications.
Material Configuration:
- Body & Bonnet: Forged steel (A105 carbon steel, A350 LF2 low-temperature steel, A182 F316 stainless steel) for high strength; tensile strength ≥485MPa (A105) to resist pressure deformation.
- Ball & Stem: A182 F304/F316 stainless steel, with ball surfaces precision-ground to Ra ≤0.8μm for tight sealing.
- Seal: Metal-to-metal (F316/Stellite-coated) with spring-loaded seats to compensate for thermal expansion, ensuring tightness under pressure fluctuations.
Connection Type: Flanged (RF/RTJ per ASME B16.5), butt-weld (BW per ASME B16.25), enabling secure integration with pipeline systems.
Operation: Manual (lever/gear), with gear-operated models reducing torque by 60% for easy handling of large-diameter valves; compatible with electric/pneumatic actuators for automation.
Standards Compliance: Design per API 6D/API 608/BS 5351; testing per API 598; fire-safe certification per API 607/API 6FA; materials compliant with ASTM standards.

Product Overview

III. Structural Features

Trunnion-Mounted Ball Design: The ball is supported by upper and lower trunnions, distributing pressure loads to prevent deformation under high pressure. This eliminates “ball blowdown” risk, ensuring stable operation even in flow surges—critical for Class 600+ high-pressure systems.
Metal-to-Metal Sealing: Precision-lapped metal seat and ball surfaces (Ra ≤0.8μm) form a bubble-tight seal (ANSI FCI 70-2 Class V). Spring-loaded seats automatically compensate for thermal expansion and wear, maintaining tightness across temperature cycles and long-term use.
Safety Enhancements:
- Anti-blowout stem: Stem bottom features an inverted seal structure to prevent ejection under high pressure, meeting API 600 safety standards.
- Anti-static device: 304 stainless steel spring connects the ball and body, dissipating static (resistance ≤10⁶Ω) to avoid sparks in flammable media like natural gas.
- Fire-safe design: Graphite backup seals ensure basic shut-off after fire, compliant with API 607, reducing leakage risks in fire emergencies.
Double Block and Bleed (DBB): Configurable to isolate upstream and downstream media simultaneously, with a bleed port to vent trapped pressure—enhancing maintenance safety in high-risk systems.

IV. Manufacturing Processes

Forged Material Preparation: Use high-quality forged steel billets (A105/F316), and verify the chemical composition (such as A105 C≤0.30%, Mn≤1.00%) through spectral analysis to ensure mechanical properties.Forgings undergo ultrasonic testing to eliminate internal defects like cracks or shrinkage.
Precision Machining:
- Ball & Seat: CNC grinders achieve ball roundness ≤0.01mm and surface finish Ra ≤0.8μm; seats are lapped to match ball contours, ensuring uniform contact for tight sealing.
- Body & Flange: CNC lathes machine flange sealing faces to flatness ≤0.05mm, with bolt holes drilled to ±0.1mm tolerance for pipeline alignment. Trunnions are precision-machined to ensure stable ball rotation.
Heat Treatment: Forged components undergo annealing (650-700℃) to relieve internal stress, reducing deformation risks during operation. Metal seats may be Stellite-coated (hardness ≥55 HRC) for wear resistance.
Assembly & Testing:
- Seat Assembly: Spring-loaded seats are pre-tested at 1.5×rated pressure to validate compensation capability, ensuring consistent contact with the ball.
- Performance Testing: Each valve undergoes API 598 testing: hydrostatic shell test (1.5×rated pressure, 30 minutes) with no leakage; gas tightness test (0.6MPa nitrogen) with leakage ≤0.1×10⁻⁶ mL/s; operation test (100+ cycles) to verify smooth actuation.

Valve Details

V. Product Advantages

High-Pressure Stability: Trunnion mounting and forged steel body withstand Class 2500 (42MPa) pressure, outperforming floating ball valves in high-pressure systems by 30% in service life.
Durable Metal Sealing: Metal-to-metal seats resist abrasion, corrosion, and high temperatures, lasting 5× longer than soft seals in abrasive media (e.g., crude oil with particulates).
Safety & Compliance: Integrates anti-blowout, anti-static, and fire-safe features, meeting strict safety requirements in oil, gas, and petrochemical industries with flammable or toxic media.
Easy Maintenance: Flanged design enables in-line maintenance; DBB function allows safe pressure venting during repairs, reducing downtime by 40% compared to non-DBB valves.
Wide Compatibility: Materials like F316 stainless steel and duplex alloys adapt to corrosive environments (e.g., seawater, sour gas), while low-temperature steel (LF2) handles cryogenic media like LNG.

Application

VI. Application Fields

Oil & Gas Industry: Upstream (wellhead, gathering lines) for crude oil and natural gas; midstream (transmission pipelines) for high-pressure gas transport; downstream (refineries) for process loops and storage tank farms.
Petrochemical & Chemical: Handles hydrocarbons, solvents, and corrosive media in reaction systems, distillation columns, and transfer pipelines, where metal sealing resists chemical erosion.
Power Generation: Regulates high-pressure steam in boiler feed lines, turbine bypass systems, and flue gas desulfurization, withstanding thermal cycling and pressure fluctuations.
Water & Industrial Systems: Controls high-pressure water in desalination plants and industrial circulation loops, with forged steel bodies resisting corrosion from mineral-rich media.