DQ347H Three-Piece Cryogenic Ball Valve Overview

The DQ347H Three-Piece Cryogenic Ball Valve is a high-performance ball valve specifically engineered for cryogenic services. It features a three-piece body construction and is operated by a worm gear drive. This valve is suitable for ultra-low temperature media such as Liquefied Natural Gas (LNG), liquid oxygen, liquid nitrogen, liquid argon, and liquid ethylene.The valve utilizes a three-piece bolted body construction, consisting of two end pieces and a central body section. This design facilitates easy online maintenance and replacement of sealing components without removing the entire valve from the pipeline. The valve body and key components are manufactured from materials such as LCB low-temperature carbon steel, CF8 stainless steel, or forged stainless steel (F304/F316L). These components undergo deep cryogenic treatment to eliminate residual stresses, ensuring excellent low-temperature toughness and dimensional stability at temperatures as low as -196°C.The valve incorporates an extended bonnet design, which positions the stuffing box away from the cold zone. This prevents the packing from freezing and mitigates valve stem seizure, ensuring reliable operation.This valve is widely used in LNG terminals, air separation units, cryogenic storage and transportation systems, and low-temperature installations in the petrochemical industry. It is a critical piece of equipment for achieving reliable shut-off under ultra-low temperature working conditions.

DQ347H Three-Piece Cryogenic Ball Valve Product Image

DQ347H Three-Piece Cryogenic Ball Valve Features

1.  Convenient Maintenance with Three-Piece Design: The valve body utilizes a three-piece bolted construction. This allows for internal inspection, cleaning, or replacement of seals on the central section without completely removing the valve from the pipeline, significantly reducing maintenance downtime.

2.  Cryogenic Treatment and Low-Temperature Materials: Key components are manufactured from low-temperature resistant stainless steel or low-temperature alloy steel. They undergo deep cryogenic treatment to relieve stress and strictly control low-temperature impact toughness, ensuring dimensional stability at -196°C and preventing brittle fracture and leakage due to deformation.

3.  Extended Bonnet Anti-Freezing Design: The long-neck bonnet structure effectively lengthens the path for cold conduction, keeping the stuffing box in a higher temperature zone. This prevents the packing from freezing and the valve stem from seizing, ensuring flexible and reliable operation at cryogenic temperatures.

4.  Smooth Operation with Worm Gear Drive: Equipped with a worm gear actuator, the valve provides high output torque, requiring less effort for operation. It ensures smooth and reliable opening and closing, allowing for precise control under cryogenic conditions. During manual operation, do not apply additional force after the position indicator shows fully open or closed.

5.  Automatic Pressure Relief Safety Structure: The valve seat features an automatic pressure relief design. If the pressure of the medium inside the valve cavity exceeds the spring preload force, the downstream seat retracts away from the ball. This safely relieves the abnormally high pressure caused by medium vaporization, preventing over-pressurization.