Description

Technical Data Sheet

Cryogenic Floating Ball Valve

Model: DQ41F / C31-CRYO Series / BS6364 Compliant

1. Product Overview

This cryogenic floating ball valve is specially designed for handling liquefied gases and low-temperature media down to -196°C. It features an extended bonnet to protect the packing and actuator from extreme cold, ensuring reliable shut-off and safe operation in cryogenic services. The floating ball design provides excellent sealing performance under low pressure.

2. Design Standards & Specifications

3. General Specifications

4. Material Specifications (Cryogenic Grade)

5. Key Design Features (BS 6364 Compliance)

• Extended Bonnet (Long Neck Design): The bonnet is extended to ensure a minimum distance (usually 250mm for -196°C) between the valve body and the packing flange. This allows the stem seal to remain at ambient temperature, preventing ice formation and actuator damage. The stem extension ratio is typically ≥4:1 .

• Pressure Relief Hole: A relief hole is drilled on the upstream side of the ball (or in the ball face) to automatically relieve any abnormal pressure build-up in the valve cavity caused by vaporization of trapped liquid .

• Blow-Out Proof Stem: The stem is internally retained by the body, ensuring it cannot be ejected by line pressure even if the packing gland is removed .

• Anti-Static Device: A spring-loaded plunger or contact mechanism ensures electrical continuity between the ball, stem, and body to prevent static charge accumulation .

• Cryogenic Treatment: All pressure-containing parts are subjected to cryogenic treatment (deep cooling) to stabilize the material structure and prevent dimensional changes at low temperatures. Impact testing at -196°C is performed per BS 6364 .

• Clean Assembly: Valves for oxygen or critical services are assembled in a clean environment to remove hydrocarbons and particles .

6. Performance Data (BS 6364 Requirements)

7. Principal Dimensions (Reference – PN16/Class150)

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

8. Applications

• LNG (Liquefied Natural Gas): Liquefaction plants, receiving terminals, storage tanks, and tankers .

• Air Separation: Liquid oxygen (LOX), liquid nitrogen (LN2), liquid argon (LAR) .

• Petrochemical: Ethylene, propylene, ethane, and other cryogenic hydrocarbons .

• Industrial Gases: Liquid hydrogen, liquid helium, CO2 .

• Food & Beverage / Medical: Cryogenic storage and processing .

9. Testing & Certification (Mandatory for Cryogenic Valves)

Each valve shall undergo the following tests in accordance with BS 6364 or equivalent standards:

1. Ambient Temperature Tests: Shell test, backseat test, and seat leakage test at room temperature.

2. Cryogenic Type Test: Valves are tested at -196°C (in liquid nitrogen) to verify:

   • Shell integrity at low temperature.

   • Seat leakage rate (meeting BS 6364 requirements).

   • Operational torque and functional cycling .

3. Material Impact Testing: Certificates for Charpy V-Notch impact tests at -196°C for body, bonnet, and bolting materials.

4. Cleanliness Certification: For oxygen service (ISO 15848 Class C or equivalent) .

10. Ordering Information

Please specify the following to ensure correct cryogenic valve selection:

1. Size, Pressure Rating & Bore: (e.g., 4″ x 4″ – Class 300 Full Bore)

2. Body / Ball / Stem / Seat Materials: (Cryogenic grade, e.g., A352 LCC Body, PCTFE Seat)

3. End Connections: (e.g., ASME B16.5 RF Flanges)

4. Service Conditions: Media (e.g., LNG, LOX), Operating Temperature (-196°C), and Pressure.

5. Certification Requirements: BS 6364 Type Test, NACE MR0175, Fire Safe (API 607), etc.

6. Operation: Manual (Lever/Gearbox), Pneumatic, or Electric Actuator.