III. Features Description

• Trunnion Mounted Stability: The ball is fixed by upper and lower trunnions, transferring fluid pressure loads to the trunnion bearings instead of the seat. This eliminates ball displacement even at 900lb pressure, avoiding seat wear and ensuring consistent sealing—critical for high-pressure steam systems where leakage risks energy loss or safety hazards.
• 3-Piece Structure: The valve body splits into three bolted sections (two end caps + middle section), allowing easy disassembly for maintenance. Internal components (ball, seat, trunnions) can be inspected or replaced without removing the valve from the pipeline, reducing downtime in critical systems.
• High-Temperature Sealing: Molon seats retain elasticity at high temperatures, maintaining tight contact with the ball to achieve ANSI/FCI Class VI leakage (near-zero). For fire safety, a fireproof sealing ring between the ball and seat forms a metal-to-metal backup seal if the soft seat degrades, meeting API 607 standards.
• Gearbox Operation: The integrated gearbox reduces operating torque by 50% compared to direct manual operation, making it feasible to control DN300 valves under high pressure. This ensures smooth, precise actuation without excessive force, extending service life of stem and seals.
• F304L Corrosion Resistance: F304L stainless steel resists corrosion from steam condensate, water, and mild chemicals, avoiding rust-related jamming or leakage. Its low carbon content prevents intergranular corrosion in high-temperature, high-humidity environments—common in steam systems.

IV. Manufacturing Processes

• Material Validation: F304L stainless steel undergoes spectral analysis to verify chemical composition (Cr ≥18%, Ni ≥8%, C ≤0.03%) and ultrasonic testing to detect internal defects, ensuring corrosion resistance and structural strength.
• Precision Forging & Machining: Body and ball are forged from F304L to eliminate internal pores, then CNC-machined to tight tolerances (±0.03mm). The ball’s sealing surface is ground to Ra ≤0.8μm for uniform contact with the seat; trunnion bearings are machined for smooth rotation.
• Assembly & Trunnion Integration: Trunnions are press-fitted into the body and welded for stability; seats are pre-loaded with springs to compensate for wear. A torque test confirms the gearbox operates smoothly with the stem, with 50+ open/close cycles verifying no jamming.
• Testing:
  • Hydrostatic Test: Body tested at 22.5MPa (1.5×900lb) for 30 minutes to check for structural leaks; seat tested at 16.5MPa (1.1×900lb) with water to confirm no leakage.
  • High-Temperature Test: Valve is heated to steam-rated temperatures, operated 100+ cycles to verify seat sealing and trunnion stability under thermal expansion.
  • Fire-Safe Test: API 607 compliance verified by exposing the valve to 750℃ fire, then testing for post-fire sealing integrity.