DD663H Pneumatic Cryogenic Butterfly Valve (Online Repairable) Overview

The DD663H pneumatic Cryogenic butterfly valve is a specialized valve designed for flow control and shut-off of -196°C grade Cryogenic media such as liquefied natural gas (LNG), liquid oxygen, liquid nitrogen, liquid helium, and liquid ethylene. It features a butt-weld connection and is driven by a pneumatic actuator, enabling remote automatic control and flow regulation. The valve body and critical components are made of LCB low-temperature carbon steel, CF8 stainless steel, or forged F304/F316L stainless steel, all subjected to cryogenic treatment to eliminate residual stress and ensure low-temperature toughness and dimensional stability at -196°C. The valve incorporates an extended bonnet design, keeping the packing away from the low-temperature zone to prevent packing freeze-up and stem seizure. This valve is widely used in automated Cryogenic systems such as LNG terminals, air separation units, and cryogenic liquefaction plants.

DD663H Pneumatic Cryogenic Butterfly Valve (Online Repairable) Product Image

DD663H Pneumatic Cryogenic Butterfly Valve (Online Repairable) Features

1.  Pneumatic Actuation for Remote Control: Equipped with a pneumatic actuator that accepts control signals for automatic opening/closing and flow regulation, facilitating integration into automated systems. The pneumatic device typically consists of an air supply, air control valve, and actuator mechanism, enabling remote operation.

2.  Butt-Weld Connection for Permanent Seal: The butt-weld ends are welded directly to the pipeline, forming an integral connection. This completely eliminates potential leak points associated with flanged connections, meeting the absolute sealing requirements of Cryogenic service.

3.  Cryogenic Treatment and Low-Temperature Materials: All critical components are made from low-temperature resistant stainless steel or low-temperature alloy steel. They undergo cryogenic treatment to relieve stress. The low-temperature impact toughness of materials is strictly controlled to ensure dimensional stability at -196°C and prevent brittle fracture.

4.  Reliable Bidirectional Sealing Structure: Utilizes a bidirectional sealing design where both the seat and the disc provide sealing capability. The seat is typically made of hard alloy material to ensure reliable sealing between the seat and disc.

5.  Extended Bonnet Anti-Freeze Design: Features a long-neck bonnet structure that effectively lengthens the cold conduction path. This keeps the packing area at a higher temperature, preventing packing freeze-up and stem seizure, ensuring flexible and reliable operation under cryogenic conditions.

6.  Simple Structure and Easy Maintenance: The pneumatic cryogenic butterfly valve has a relatively simple structure, consisting of components such as the body, disc, stem, and seals. This simplicity facilitates convenient maintenance and repair.