Description

Technical Data Sheet: 6″ (DN150) Class 300 Cryogenic Floating Ball Valve

1. General Description

This data sheet covers a 6-inch (DN150) Class 300 cryogenic floating ball valve with a two-piece, side-entry flanged body and extended bonnet design. The valve is precision cast from ASTM A351 CF8 stainless steel and is specifically engineered for low-temperature and cryogenic service down to -196°C. It features a PCTFE (Polychlorotrifluoroethylene) seat for reliable sealing at cryogenic temperatures, a manual gear operator for reduced operating torque, and an ISO 5211 top mounting pad for straightforward actuator integration.

The extended bonnet design is a critical feature that keeps the stem packing and gland away from the cryogenic media, ensuring the packing operates above 0°C and preventing seal failure due to low temperature.

2. Nameplate Data (Confirmed from Images)

3. Design Codes & Standards

4. Main Technical Specifications

5. Materials of Major Parts

Note on PCTFE: PCTFE (Polychlorotrifluoroethylene), also known as Kel-F®, is the most widely specified cryogenic seat material in the industry. It maintains a tight seal at temperatures as low as -196°C and provides reliable sealing for LNG, liquid nitrogen, and other cryogenic media.

6. Principal Dimensions (6″ Class 300 RF)

Note: Face-to-Face dimension per ASME B16.10 for Class 300 6″ flanged ball valves is 356 mm (14.02″). Extended bonnet length per BS 6364 for non-cold box applications is minimum 250 mm.

7. Cryogenic Treatment Process

All pressure-containing and sealing components are subjected to cryogenic treatment to ensure dimensional stability and prevent low-temperature embrittlement.

Purpose: Cryogenic treatment stabilizes the material structure, eliminates dimensional changes caused by retained austenite transforming to martensite, and ensures sealing fit precision at low temperatures.

8. Pressure Test Data

8.1 Ambient Temperature Tests (API 598)

8.2 Cryogenic Test (BS 6364)

9. Impact Test Requirements (ASME B16.34)

Note: All cryogenic service materials must pass Charpy V-notch impact testing at the minimum design temperature or colder. Test specimens must be cooled to the design temperature prior to impact testing.

10. Gear Operator Specifications

11. Design Features for Cryogenic Service

1. Extended Bonnet: Keeps packing and gland at ambient temperature, preventing seal failure and ice formation. Minimum 250 mm extension per BS 6364.

2. PCTFE Seat: Excellent low-temperature performance and chemical stability, suitable for long-term use at -196°C.

3. Cryogenic Treatment: Dimensional stability and prevention of low-temperature embrittlement.

4. Cavity Relief: Prevents abnormal pressure buildup caused by vaporization of trapped cryogenic liquid.

5. Anti-Static Device: Prevents static electricity accumulation in flammable media service.

6. Fire-Safe Design: Metal seat backup ensures sealing integrity in external fire conditions (API 607).

7. Blow-out Proof Stem: Prevents stem ejection under pressure.

8. Drip Plate: Prevents condensation from entering insulation (optional).

12. Applications

• LNG liquefaction, regasification, and storage terminals

• Air separation units (ASU)

• Liquid oxygen, liquid nitrogen, and liquid argon systems

• Ethylene storage and transportation

• LPG and ammonia systems

• Cryogenic rocket engine testing

13. Installation & Maintenance Notes

1. Installation Orientation: The valve should be installed with the extended bonnet vertically upward to keep the packing in the warmest possible position. Note the flow arrow on the body.

2. Insulation: The extended bonnet must be wrapped with cryogenic insulation (e.g., PIR/foam glass). The insulation should not cover the packing gland to allow for maintenance and inspection.

3. Flange Bolting: Use ASTM A320 L7 stud bolts and A194 Gr.4 nuts for cryogenic service. Tighten in a diagonal sequence to the torque specified in the IOM manual.

4. Operation: Cycle the valve slowly to avoid static electricity generation. Operating torque may increase slightly at cryogenic temperatures; this is normal.

5. Maintenance: Periodically inspect the packing gland for leakage. If leakage occurs, tighten the gland nuts evenly. Before returning to service after maintenance, re-perform cryogenic testing as required.

14. Ordering Information

To ensure correct supply, please specify:

• Nominal Size: 6″ (DN150)

• Pressure Rating: Class 300

• Body Material: ASTM A351 CF8 / CF8M

• Ball Material: CF8 / SS304 / SS316

• Seat Material: PCTFE (Standard for Cryogenic)

• Connection Standard: ASME B16.5 Class 300 RF

• Operation: Gear Operator (Handwheel)

• Cryogenic Test: BS 6364 (Required)

• Special Requirements: (e.g., fire-safe, anti-static, NACE MR0175, oxygen cleaning)

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Disclaimer: This data sheet is compiled based on visual inspection of the provided images and standard industry specifications for a 6″ Class 300 cryogenic floating ball valve. Exact dimensions, materials, and performance data may vary by manufacturer. Please confirm all critical parameters with the original equipment manufacturer (OEM) before procurement or installation.