API 6FA Ball Valve

1. Compliance and Standards‌

• ‌API 6FA‌: Compliant with fire-test requirements, including a 30-minute burn test and post-fire leakage criteria.
• ‌API 6D‌: Design and manufacturing adhere to API 6D (Pipeline Valves) for quality, materials, and testing.
• ‌ASME B16.34‌: Pressure-temperature ratings and materials conform to ASME standards.
• ‌ISO 10497‌: May also comply with international fire-testing standards.

2. Design Features‌

• ‌Fire-Safe Design‌:
  • ‌Seals‌: Graphite or fire-resistant elastomers for stem and seat seals to prevent leakage during/after fire exposure.
  • ‌Metal-to-Metal Seats‌: Secondary metal seating surfaces ensure sealing if soft seals degrade in fire.
  • ‌Emergency Sealant Injection‌: Optional feature to inject sealant into the cavity during emergencies.
• ‌Anti-Static Device‌: Ensures electrical continuity between the ball and body to prevent static discharge.
• ‌Blowout-Proof Stem‌: Stem retention design prevents stem ejection under pressure.
• ‌Full/Reduced Bore‌: Available in full-bore (for minimal pressure drop) or reduced-bore configurations.
• ‌Floating or Trunnion-Mounted Ball‌:
  • ‌Floating Ball‌: Suitable for low-to-medium pressure.
  • ‌Trunnion-Mounted Ball‌: Ideal for high-pressure/high-temperature (HPHT) applications.

3. Material Specifications‌

• ‌Body Materials‌:
  • Carbon steel (e.g., ASTM A216 WCB).
  • Stainless steel (e.g., ASTM A351 CF8M, CF3M).
  • Alloy steels (e.g., ASTM A352 LCC, LC3).
• ‌Ball and Stem‌:
  • Stainless steel (316/316L) with hard coatings (e.g., stellite, tungsten carbide) for wear resistance.
• ‌Seats‌:
  • PTFE, RPTFE, or PEEK for standard service.
  • Metal seats (e.g., Inconel, stellite) for fire-safe or high-temperature applications.
• ‌Bolting‌: ASTM A193 B7/B8 for high-strength, fire-resistant performance.

4. Pressure and Temperature Ratings‌

• ‌Pressure Class‌: ANSI 150 to 2500 (or higher for custom designs).
• ‌Temperature Range‌:
  • Standard: -29°C to 200°C (-20°F to 392°F).
  • Extended range (with special materials): -196°C to 600°C (-321°F to 1112°F).

5. Fire Safe Test Requirements‌

• ‌Fire Exposure‌: 30-minute burn at 750–1000°C (1382–1832°F).
• ‌Leakage Criteria‌:
  • ‌Post-Fire Seat Leakage‌: ≤ 600 cm³/min per inch of nominal diameter (API 6FA).
  • ‌Shell Leakage‌: None allowed during/after testing.

6. End Connections‌

• ‌Flanged Ends‌: ASME B16.5 or B16.47 flanges.
• ‌Butt-Weld Ends‌: ASME B16.25 for seamless pipeline integration.
• ‌Socket Weld/Threaded Ends‌: Optional for smaller sizes.

‌7. Testing and Certification‌

• ‌Factory Acceptance Testing (FAT):
  • Hydrostatic shell test (1.5x rated pressure).
  • Seat leakage test (per API 598/API 6D).
  • Fire test certification (per API 6FA).
• ‌Third-Party Inspection‌: Available via DNV, ABS, or Lloyds Register.

8. Optional Features‌

• ‌Locking Device‌: Secures the valve in open/closed positions.
• ‌Cavity Relief‌: Prevents overpressure in the valve body cavity.
• ‌Extended Bonnet‌: For cryogenic or high-temperature insulation.
• ‌Actuation‌: Pneumatic, hydraulic, or electric actuators for remote operation.