Description

1½” (DN40) Class 150 Cryogenic Extended Bonnet Floating Ball Valve – Technical Data Sheet

1. General Information

2. Materials of Construction

Material Note: According to GB/T 24925 and ASME B16.34, for valves operating below -100°C, body materials must be austenitic stainless steels with a face-centered cubic lattice (e.g., ASTM A351 CF8/CF8M, A182 F304/F316). CF8M (316 SS) has a minimum working temperature of -254°C, far superior to low-temperature carbon steels (e.g., LCB is -46°C, LC3 is -101°C).

3. Dimensions (Per Drawing)

Note: The extended bonnet length (distance from body centerline to packing base) is designed to keep the packing working temperature above 0°C, preventing seal failure due to low temperatures. BS 6364 specifies the minimum extension length for cold box valves. For ball valves operating below -50°C, the neck length is generally no less than 250mm.

4. Extended Bonnet Design

The cryogenic ball valve features an extended bonnet design with the following critical functions:

1. Protects Packing: Keeps the packing away from the cryogenic media, ensuring the packing working temperature remains above 0°C to prevent seal failure.

2. Facilitates Insulation: The extended neck allows for easy wrapping of insulation materials (e.g., PIR/foam glass) to prevent cold energy loss and frost formation.

3. Drip Plate Design: A drip plate on the extended neck prevents condensation from entering the insulation layer, maintaining insulation effectiveness.

4. Cavity Self-Relieving: Cryogenic media expands rapidly when vaporized. The valve features a cavity pressure relief structure to safely vent abnormal pressure buildup in the cavity.

5. Cryogenic Treatment Process

All valve parts operating below -100°C must undergo cryogenic treatment to prevent low-temperature brittleness and dimensional changes caused by phase transformations. Specific requirements are as follows:

6. Applicable Standards

7. Performance Specifications

8. Cryogenic Test Method (BS 6364)

According to BS 6364, cryogenic testing is performed as follows:

1. Test Temperature: -196°C (Liquid Nitrogen)

2. Test Method: Immerse the valve in a liquid nitrogen cooling bath. Once the valve reaches test temperature, pressurize and perform open-close cycling, measuring leakage at the seat and stem packing.

3. Test Requirements: Zero leakage required for body, stem, and seat sealing areas.

4. Sampling Ratio: For valves operating below -55°C, at least 10% of each type and size must undergo cryogenic testing.

9. Design Features

1. Extended Bonnet: Extended neck design keeps the packing in a normal temperature zone, improving packing seal reliability.

2. Cryogenic Treatment: Key parts undergo liquid nitrogen cryogenic treatment before finishing, ensuring low-temperature dimensional stability.

3. PCTFE Seat: Utilizes PCTFE material with excellent low-temperature performance, suitable for long-term use at -200°C.

4. Anti-Static Structure: Meets anti-static requirements, ensuring safe operation in flammable and explosive media.

5. Fire Safe Design: Complies with API 607/API 6FA, maintaining seal integrity in external fire conditions.

6. Cavity Self-Relieving: Prevents abnormal pressure buildup caused by vaporization of cryogenic media, ensuring valve safety.

7. Double-Layer Packing: Double-layer stem packing with Belleville spring assembly ensures reliable sealing.

8. Drip Plate: Prevents condensation from entering the insulation layer, protecting insulation effectiveness.

9. Two-Piece Body: Facilitates easy maintenance and repair.

10. Installation & Usage Notes

1. Installation Orientation: The valve can be installed in any orientation, but it is recommended to install the extended bonnet vertically upward to ensure the packing operates at optimal temperature. Note the flow arrow on the valve body.

2. Insulation: After installation, the extended bonnet must be wrapped with insulation material to prevent cold energy loss and external frost. The insulation should not cover the packing gland to allow for maintenance and inspection.

3. Flange Connection: The 1½” Class 150 flange has 4-φ16 bolt holes with a bolt circle diameter of 98.5mm. Use matching cryogenic bolts (ASTM A320 L7) and tighten evenly in a diagonal sequence.

4. Operating Precautions:

   • Valves should be used in fully open or fully closed positions; throttling is not recommended.

   • Operate slowly to avoid static electricity generated by rapid flow of cryogenic media.

   • Operating torque may increase slightly at low temperatures; this is normal.

5. Maintenance:

   • Periodically check if the packing gland is loose. If leakage occurs, tighten promptly.

   • Before restarting after long-term storage, perform an operational test.

   • If replacing seats or seals, use original manufacturer parts and re-perform cryogenic testing.

11. Ordering Information

Please provide the following information when ordering:

• Nominal Size: 1½” (DN40)

• Pressure Rating: Class 150LB

• Body Material: CF8M (316 SS)

• Seat Material: PCTFE

• Connection Type: Flanged RF (ASME B16.5 Class 150)

• Operation: Lever

• Extended Bonnet Length Requirement

• Special Requirements (e.g., cryogenic test certification, third-party inspection, ISO 15848 micro-leakage testing, etc.)

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Disclaimer: This data sheet is compiled based on product drawings, physical photographs, and general industry standards. Some parameters are reference values. Actual product parameters may vary due to manufacturer design and production differences. It is recommended to confirm final technical specifications with the supplier before procurement.