Description

Technical Data Sheet

Cast 3-Piece Trunnion Mounted Ball Valve

Model: CQ347F / 3PC-Cast Series / API 6D Compliant

1. Product Overview

This cast 3-piece trunnion mounted ball valve combines the complex geometry capabilities of casting with the maintenance-friendly features of a three-piece body design. The valve consists of three cast sections (left body, center body, and right body) bolted together, allowing for easy removal of the center section for maintenance without disturbing the pipeline ends. The trunnion-mounted ball provides stable operation under high differential pressure, making it ideal for large diameter and high-pressure applications .

2. Design Standards & Specifications

3. General Specifications

4. Material Specifications (Cast Body Series)

5. Casting Advantages

• Complex Geometry: Casting allows for optimized flow paths, integrally cast mounting pads, and complex internal features that would be difficult or impossible to machine from forgings .

• Cost-Effective for Large Sizes: For valves DN300 (12″) and above, casting is significantly more economical than forging or fabricated construction .

• Design Flexibility: Casting enables variable wall thickness, ribbed structures for strength, and custom end connections .

• Smooth Flow Transition: Cast bodies can incorporate smooth radius transitions reducing turbulence and pressure drop .

• Integral Features: Mounting pads, drain/boss connections, and identification markings can be cast directly into the body .

6. Key Design Features

• 3-Piece Cast Bolted Construction: Three separate cast sections bolted together with studs or bolts. This design allows for in-line maintenance where the center section can be removed without disturbing pipeline ends . The bolted construction accommodates various end connection types on the same center section .

• Trunnion Mounted Ball: The ball is supported by two fixed trunnion shafts with bearings, eliminating seat loading under high differential pressure. This reduces operating torque by up to 60% compared to floating ball valves at Class 600+ and ensures smooth operation even in large diameters .

• Dual Seat Design with Spring Loading: Primary soft seat (PTFE/PEEK) provides zero-leakage sealing during normal operation. Secondary metal seat (Inconel/Stellite) serves as an emergency backup in case of fire or soft seat failure. Springs maintain constant seat-to-ball contact regardless of pressure conditions .

• Double Block & Bleed (DBB) Capability: The valve seals against pressure from both directions simultaneously, allowing the body cavity to be vented to confirm seal integrity per API 6D requirements .

• Blowout-Proof Stem: The stem is internally retained by the body or a retaining plate, ensuring it cannot be ejected by line pressure even if the packing gland is removed .

• Anti-Static Device: Spring-loaded plungers or contacts ensure electrical continuity between the ball, stem, and body (resistance ≤10Ω), preventing static charge accumulation in flammable service .

• Cavity Pressure Relief: Automatic pressure relief seats allow the body cavity to relieve excess pressure to the upstream or downstream pipe, preventing over-pressurization due to thermal expansion .

• ISO 5211 Mounting Pad: Integral cast top flange allows direct mounting of actuators without brackets, ensuring precise alignment .

• Self-Relieving Seats: Optional single-piston-effect (SPE) seats automatically relieve cavity pressure without external valves .

7. Casting Quality Requirements

8. Performance Data

9. Principal Dimensions (Reference – Class 300 Flanged)

Note: Dimensions are for reference only. Final dimensions to be confirmed based on manufacturer’s detailed drawing and pressure class.

10. Applications

• Pipeline Transmission: Natural gas, crude oil, and refined product pipelines (large diameter)

• Refineries: Fluid catalytic cracking (FCC), hydrocracking, and high-temperature hydrocarbon services

• Petrochemical Plants: Ethylene, propylene, and other process plants requiring large valves

• LNG Terminals: Liquefied natural gas receiving and storage (with extended bonnet)

• Offshore Platforms: Production manifolds, pipeline end manifolds (PLEM)

• Power Generation: Steam, feedwater, and fuel systems

• Water & Wastewater: Large diameter water transmission (AWWA series)

• Mining: Slurry services (with special coatings and hardened trim)

11. Testing & Certification

Each valve shall be manufactured, tested, and certified in accordance with:

1. Material Test Certificates (MTC): EN 10204 Type 3.1 or 3.2 certification for pressure-containing cast parts including chemical analysis and mechanical properties (Tensile, Yield, Elongation)

2. Heat Treatment Certificates: Documented heat treatment cycles (normalizing, tempering, solution annealing)

3. NDE Reports:

   • Visual inspection per MSS SP-55

   • Radiographic (RT) or Ultrasonic (UT) examination reports (if specified)

   • Magnetic Particle (MT) or Dye Penetrant (PT) reports on critical surfaces and repair welds

4. Hydrostatic Testing: Shell and seat test reports per API 598 with test pressures and duration recorded

5. Pneumatic Testing: Low-pressure seat test reports (if specified)

6. Fire-Safe Certification: API 607 / API 6FA type test certificate for fire-safe design

7. Fugitive Emissions Test: ISO 15848-1 certificate (if specified)

8. NACE Compliance: Statement of compliance with NACE MR0175 for sour service

9. SIL Rating: Safety Integrity Level certification (if required)

10. Positive Material Identification (PMI): Verification of alloy castings

12. Ordering Information

Please specify the following to ensure correct valve selection:

1. Size & Pressure Rating: (e.g., 24″ – Class 300)

2. Body Material: (e.g., Cast ASTM A216 WCB, A351 CF8M, A352 LCC)

3. End Connections: (Flanged RF/RTJ, Butt-Weld, Hub end)

4. Bore: Full Bore or Reduced Bore

5. Ball & Seat Material: (e.g., CF8M Ball + RPTFE Seat, or Metal seats with temperature range)

6. Seat Design: DPE (Double Piston Effect) or SPE (Single Piston Effect)

7. Operation: Manual (Gear), Pneumatic, Electric (specify voltage/control), Hydraulic

8. Special Coatings: HVOF, ENP, Chrome plating for ball (if required)

9. Special Requirements: Fire-safe, NACE, Cryogenic, Fugitive Emissions, SIL, Sour Service

10. Certifications: API monogram, PED, ATEX, EAC, CRN, etc.