Description

Cryogenic Floating Ball Valve Technical Data Sheet

(Cast Stainless Steel, Floating Ball, Gear Operated, PCTFE/PEEK Seats)

1. Product Overview

Product Type: Cryogenic Floating Ball Valve
Body Material: Cast Stainless Steel (ASTM A351 CF8/CF8M/CF3M)
Ball Design: Floating Ball
Operation: Gear Operated (Worm Gear with Handwheel)
Connection Type: Flanged Ends (RF / RTJ)
Seat Material: PCTFE (Polychlorotrifluoroethylene) or PEEK (Polyetheretherketone)
Design Standard: BS 6364, API 6D, ASME B16.34, ISO 28921-1, MSS SP-134
Temperature Range:

• PCTFE Seats: -196°C ~ +120°C (LNG, Liquid Nitrogen, Liquid Ethylene)

• PEEK Seats: -196°C ~ +200°C (Higher temperature cryogenic applications)
  Nominal Size: NPS 2″ ~ 10″ (DN50 ~ DN250) [Floating ball design suitable for these sizes]
  Pressure Class: Class 150 ~ Class 600 (PN16 ~ PN100)
  End Flanges: ASME B16.5 (RF / RTJ)
  Face-to-Face Dimensions: ASME B16.10, API 6D (Long pattern)
  Testing Standard: BS 6364 (Cryogenic testing), API 598, ISO 28921-1, MSS SP-134

2. Applicable Standards & Specifications

3. Main Technical Parameters

*Note: For Liquid Hydrogen (-253°C), special material and design considerations required.*

4. Material of Construction (Cast Stainless Steel)

4.1 Standard Material Combinations for Cryogenic Service (-196°C)

4.2 Critical Design Features for Cryogenic Service

5. Floating Ball Design Features

• Floating Ball Principle: The ball is not fixed but floats between two seats. Upstream pressure pushes the ball against the downstream seat, ensuring tight shut-off. This design provides excellent sealing performance for NPS 2″~10″ sizes in cryogenic applications .

• Seat Loading: PCTFE and PEEK materials provide excellent cold flow resistance and maintain elasticity at cryogenic temperatures, ensuring consistent seat loading .

• Seat Retention: Seats are securely retained in the body or body cap with anti-extrusion rings to prevent seat movement under high differential pressure .

• Ball Surface Finish: Ball is super-finished (Ra ≤ 0.2μm) and typically chromium plated or electroless nickel plated for enhanced wear resistance and low operating torque .

6. Seat Material Selection Guide (PCTFE vs PEEK)

6.1 Recommended Seat Material by Application

7. Gear Operator Features

• Worm Gear Design: Self-locking worm gear mechanism prevents reverse rotation and ensures safe operation in all positions .

• Handwheel Operation: Large diameter handwheel provides mechanical advantage for high torque requirements at cryogenic temperatures .

• Low Temperature Lubrication: Gearbox filled with low-temperature grease (synthetic lubricants rated to -60°C or below) .

• Position Indicator: Visual open/close position indicator standard on gearbox .

• Travel Stops: Adjustable travel stops for precise open/close positioning .

• Corrosion Protection: Epoxy-coated gearbox housing (standard) or stainless steel construction (optional) .

• Mounting: Direct mounting to valve bonnet with anti-rotation key .

8. Dimensional Data (Reference – Class 150/300/600 RF Flanged)

Note: Dimensions are for reference only. Final dimensions vary by manufacturer and specific pressure rating. Extended bonnet length (E) per BS 6364 requirements. Consult GA drawing for final approval.

8.1 Face-to-Face Dimensions (L) – ASME B16.10 / API 6D (Long Pattern)

8.2 Overall Dimensions (Approximate) with Gear Operator

*Note: Stem extension length (E) is critical for cryogenic service per BS 6364 to maintain packing temperature above -50°C and prevent ice formation. Extension length increases with valve size and lower operating temperatures.*

9. Cryogenic Testing Requirements (Per BS 6364 / ISO 28921-1)

10. Installation, Operation & Maintenance Instructions

10.1 Pre-Installation

• Remove protective covers. Clean valve interior to remove debris .

• Verify valve has undergone cryogenic testing and deep cryogenic treatment per BS 6364 .

• Inspect flange faces and RTJ grooves for damage .

• Check gearbox operation and lubricant (ensure low-temperature grease) .

• Verify stem extension length meets insulation requirements .

10.2 Installation

• Ensure pipeline is clean, dry, and free from moisture, contaminants, and debris (critical for cryogenic service) .

• Install valve with flow direction matching application requirements (bidirectional capability standard for floating ball valves) .

• For RTJ flanges, use correct ring gasket material (Soft Iron for general, 316L for corrosive) .

• Ensure extended bonnet is positioned vertically (preferred) or horizontally with adequate support .

• Provide adequate insulation around body and extended bonnet to prevent ice formation and cold loss (per project specifications) .

• Support piping adequately to avoid stress on valve flanges (critical for cryogenic thermal cycling) .

• Tighten flange bolts evenly in crisscross pattern to recommended torque .

10.3 Operation

• Gear Operation: Turn handwheel clockwise to close, counter-clockwise to open. The worm gear mechanism is self-locking .

• Do not use pipe extensions or hammers on handwheel for additional leverage .

• During initial cooldown, operate valve slowly (partial strokes) to prevent thermal shock .

• Allow valve to reach thermal equilibrium before full operation .

• Monitor operating torque; any significant increase may indicate ice formation or seat damage .

10.4 Maintenance

• Regular Inspection:

  • Check extended bonnet for ice accumulation; ensure insulation is intact .

  • Inspect stem packing for leakage; live-loading should maintain seal without adjustment .

  • Verify gearbox lubricant level and condition .

• Packing Adjustment: If slight stem leakage occurs (rare with live-loaded packing), adjust gland nuts evenly only when valve is at ambient temperature .

• Major Repairs:

  • Allow valve to warm to ambient temperature slowly before disassembly .

  • Depressurize valve completely before any maintenance .

  • Replacement parts must be OEM-sourced and cryogenically treated .

  • Re-lubricate stem threads and gearbox with cryogenic-compatible lubricant .

• Spare Parts: Recommended spare parts include seat kits, stem seals, gaskets, and lubricants .

11. Ordering Information

When ordering Cryogenic Floating Ball Valves (Gear Operated, PCTFE/PEEK Seats), please specify:

1. Valve Type: Cryogenic Floating Ball Valve

2. Nominal Size: NPS ___ (DN ___)

3. Pressure Class: Class ___ (150/300/600)

4. Body Material: ASTM A351 CF8 / CF8M / CF3M

5. Ball Material: ASTM A182 F304 / F316 / F316L

6. Seat Material: PCTFE or PEEK (specify grade if required)

7. Connection Type: RF Flanged / RTJ Flanged

8. Operation: Gear Operated (Worm Gear with Handwheel)

9. Port Type: Full Bore / Reduced Bore

10. Stem Extension Length: Standard per BS 6364 or specify special length

11. Applicable Medium: ___ (LNG, LN2, LOX, etc.)

12. Operating Temperature: ___ °C

13. Special Requirements:

    • Cryogenic Test Certificate per BS 6364

    • NACE MR0175 / ISO 15156 compliance

    • Fire-Safe Design (API 607)

    • Low Emission Packing (ISO 15848)

    • Oxygen Cleaning (for LOX service)

    • Special Painting / Coating

14. Quantity Required: ___ units

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Note: This technical data sheet is a general guideline for Cast Stainless Steel Cryogenic Floating Ball Valves with Gear Operation and PCTFE/PEEK seats, designed per BS 6364 and API 6D standards. For specific project requirements, including detailed material selection, pressure class, and dimensions, please refer to the approved manufacturer’s drawing and purchase order. Specifications are subject to change without notice.