Cryogenic -196°C LNG Double-Ball Ball Valve

This product is a highly specialized Double-Ball Ball Valve ( $\text{DBB}$ ), constructed from $\text{F}316\text{L}$ stainless steel, designed for extreme low-temperature service down to $\text{-196}^\circ\text{C}$ —ideal for Liquefied Natural Gas ( $\text{LNG}$ ) applications.

Featuring a dual-ball, series-connected structure within a 3-piece side-entry design, this valve offers unparalleled sealing integrity, safety, and functionality, widely replacing complex multi-valve systems in various demanding industries.

📋 Technical Standards & Specifications

Parameter	Detail / Standard
Media Temperature	Cryogenic ( $\text{-196}^\circ\text{C}$ ) (Required for $\text{LNG}$ )
Valve Type	Fixed Ball Valve (Double-Ball $\text{DBB}$ )
Body Structure	3-Piece Side-Entry
Body Material	$\text{F}316\text{L}$ (Forged Stainless Steel equivalent to $\text{SS}316\text{L}$ )
Size Range	$\text{2}''$ to $\text{48}''$
Pressure Class	$\text{ASME CL} 150, 300, 600$ ( $\text{PN}$ Design also available)
Design Standard	$\text{API} 6\text{D}, \text{BS} 5351, \text{ASME B} 16.34$
End Standards	Flange ( $\text{ASME B} 16.5/\text{B} 16.47$ ), Butt-Weld ( $\text{ASME B} 16.25$ )
Fire Safe Test	$\text{API} 607, \text{API} 6\text{A}$
Testing Standard	$\text{API} 598, \text{API} 6\text{D}$ (100% tested before delivery)
Warranty	18 months after shipment, 12 months after installation

⭐ Advanced $\text{DBB}$ Structure and Performance Features

The $\text{DBB}$ (Double Block and Bleed) dual-ball structure is designed to outperform traditional multi-valve setups:

Dual-Ball Series Structure: Two separate balls and seat sets are contained within one compact body. This structure enables simultaneous sealing on both sides of the valve, providing absolute isolation.
Double Block and Bleed ( $\text{DBB}$ Function): Allows for the simultaneous sealing of the upstream and downstream seats. The space (or cavity) between the balls can then be vented (bled) to verify that both seals are tight, which is critical for safety and zero-leakage verification.
Low Torque Operation: Engineered with a highly effective sealing structure that ensures tight shut-off while maintaining low operating torque.
Cavity Self-Pressure Relief: Prevents dangerous over-pressurization of the internal body cavity, a vital safety feature for cryogenic service where trapped liquid can expand rapidly upon temperature increase.
Full Bore / Reduced Bore Options:
- Full Bore: Channel inner diameter matches the pipeline, providing minimal fluid resistance and easy pigging (pipeline cleaning).
- Reduced Bore: Reduces the valve’s weight and cost by approximately $30\%$ compared to full bore valves, while still offering significantly lower fluid resistance than globe valves.

🛡️ Enhanced Safety and Structural Integrity

Anti-Intrusion (Anti-Blowout) Stem: Features a reverse sealing structure where the stem is attached from the inside. The sealing force is augmented by the cavity medium pressure, preventing the stem from being ejected even if internal pressure spikes abnormally.
Fire Safe Structure: Designed to maintain effective metal-to-metal hard sealing even if soft seals are burned away during a fire, preventing medium diffusion and fire propagation ( $\text{API} 607$ ).
Anti-Static Structure: Conductive springs are placed between the ball and stem, and the stem and body, to safely discharge static electricity generated during valve operation, preventing sparks and the ignition of flammable media.
ISO $5211$ Mounting: Standardized top plate for direct mounting of pneumatic or electric actuators for automation.
Locking Device: Provided for manual operation to prevent accidental opening or closing.

🏭 Application Benefits

The $\text{DBB}$ dual-ball valve significantly streamlines piping systems:

Saves Space: Replaces the need for multiple conventional valves in a complex configuration.
Simplifies Installation: Reduces potential leak points compared to multi-flange assemblies.
Lowers Cost: Reduces material costs, installation time, and maintenance complexity.

This valve is widely used in Power Generation, Petrochemical, LNG, Shipbuilding, and Pharmaceutical industries for high-integrity hydraulic system isolation.