DD343H Hard Seal Low Temperature Butterfly Valve Overview

The DD343H flanged cryogenic butterfly valve is a specialized low-temperature valve featuring a flange connection and a triple-offset metal hard seal structure. It is suitable for ultra-low temperature media such as liquefied natural gas (LNG), liquid oxygen, liquid nitrogen, liquid argon, and liquid ethylene. The valve body and key components are made of LCB low-temperature carbon steel, CF8 stainless steel, or forged F304/F316L stainless steel. Parts designed for temperatures ≤ -101°C undergo cryogenic treatment to prevent deformation under ultra-low temperature conditions. The valve features an extended bonnet design, with the stem and bonnet extension length determined based on the temperature rating, keeping the packing away from the low-temperature zone to prevent packing freeze-up and stem seizure. The valve is operated by a worm gear drive that rotates the disc 90 degrees for opening, closing, and flow control. It is widely used in cryogenic industries such as LNG and air separation.

DD343H Hard Seal Low Temperature Butterfly Valve  Product Image

DD343H Hard Seal Low Temperature Butterfly Valve Features

1.  Extended Bonnet Anti-Freeze Design: The bonnet extension length is determined based on the temperature rating, effectively isolating cold conduction. This keeps the packing area at a higher temperature, preventing packing freeze-up and stem seizure, ensuring flexible and reliable operation.

2.  Cryogenic Treatment and Low-Temperature Materials: Critical components designed for ≤ -101°C 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.

3.  Triple-Offset Hard Seal Structure: Utilizes a triple-offset sealing design that minimizes wear between the seat and disc, providing a sealing effect that tightens as pressure increases. The disc sealing surface is overlaid with hard alloy, enhancing erosion resistance and extending service life.

4.  Bidirectional Sealing and Zero Leakage: Excellent sealing performance achieves zero leakage. The seat sealing surface is overlaid with hard alloy, providing superior sealing characteristics.

5.  Excellent Control Performance: Possesses good throttling capabilities and can function as a control valve, allowing flow adjustment anywhere within the 0 to 90-degree rotation range.

6.  Safety Protection Design: Features a blowout-proof stem design for operational safety. A drip plate design effectively prevents condensate from flowing into the insulation layer. Stem packing utilizes low-emission materials to ensure compliance with low-leakage requirements.