DN100 PN40 3-Piece Trunnion Mounted Hard Metal Seal BW Ball Valve for Flow Control

I. Product Overview

II. Key Attribute Parameters

• Size Range: 2″~24″ (DN50~DN600), covering small to large-diameter pipelines to meet flow requirements in process loops, transmission lines, and high-pressure systems.
• Pressure Rating: PN16~PN420 (Class 150~2500), with PN40 (6.4MPa) as a common specification, suitable for medium to ultra-high pressure applications.
• Temperature Range: -46℃~450℃, with material upgrades (e.g., alloy steel) enabling operation up to 550℃ for high-temperature steam or thermal fluid systems.
• Material Configuration:
  • Body: Carbon steel (WCB), stainless steel (316), or duplex stainless steel, selected for corrosion resistance and structural strength.
  • Ball & Stem: 316 stainless steel or Stellite-coated alloys, ensuring wear resistance and compatibility with abrasive media.
  • Seal: Hard metal-to-metal (316 stainless steel/Stellite), with spring-loaded seats to compensate for thermal expansion and wear.
• Connection Type: Butt-weld (BW per ASME B16.25), providing a permanent, leak-tight joint that eliminates flange-related leakage risks, ideal for high-pressure or vibration-prone systems.
• Operation: Manual (gear), electric, or pneumatic, with gear-operated models reducing torque by 60% for easy handling of large-diameter valves.
• Standards Compliance: Design per API 6D, ASME B16.34; testing per API 598; fire-safe certification per API 607, ensuring compatibility with global industrial standards.

III. Structural Features

• 3-Piece Split Body: The valve body splits into three sections (two end caps and a middle section) connected by bolts, allowing easy disassembly for in-line maintenance (ball, seat, or stem replacement without removing the valve from the pipeline). This reduces downtime by 50% compared to 1-piece or 2-piece valves.
• Trunnion-Mounted Ball: The ball is supported by upper and lower trunnions, distributing pressure loads to prevent deformation under high pressure. This design eliminates “ball blowdown” (displacement due to flow force), ensuring stable operation even in pressure surges—critical for Class 600+ systems.
• Hard Metal Sealing: Precision-lapped metal seats 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.
• Butt-Weld Connection: Welded joints (full penetration) create a seamless transition between valve and pipeline, minimizing pressure drop and eliminating flange gasket leakage risks. Suitable for buried pipelines or systems with strict leakage requirements (e.g., toxic or flammable media).
• Safety Enhancements: Anti-blowout stem (prevents ejection under high pressure), anti-static device (dissipates static to avoid sparks), and fire-safe graphite backup seals (API 607 compliant) for hazardous environments.

IV. Manufacturing Processes

• Material Forging: Body, ball, and trunnion components are forged (forging ratio ≥3) to eliminate internal defects, enhancing strength. Raw materials undergo spectral analysis (e.g., 316: 16-18% Cr, 10-14% Ni) and ultrasonic testing to verify integrity.
• Precision Machining:
  • Ball & Seats: 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 & Weld Ends: CNC lathes machine butt-weld ends to dimensional accuracy (±0.5mm) for proper fit-up with pipelines; trunnion bores are precision-machined to ensure smooth ball rotation.
• Heat Treatment: Forged components undergo annealing (650-700℃) to relieve stress; metal seats are Stellite-coated (hardness ≥55 HRC) for wear resistance, then tempered to enhance toughness.
• Assembly & Testing:
  • Seats are pre-loaded with springs and tested at 1.5×rated pressure to validate compensation capability.
  • Each valve undergoes API 598 testing: hydrostatic shell test (1.5×rated pressure, 30 minutes), gas tightness test (0.6MPa nitrogen, leakage ≤0.1×10⁻⁶ mL/s), and 1000+ operation cycles to verify durability.