DD343F Soft Seal Low Temperature Flange Butterfly Valve Overview

The DD343F flanged low-temperature butterfly valve is a cryogenic-service-specific valve featuring a flanged connection and a triple eccentric sealing 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 manufactured from LCB low-temperature carbon steel, CF8 stainless steel, or F304/F316L forged stainless steel, all of which undergo deep cryogenic treatment to eliminate residual stress, ensuring low-temperature toughness and dimensional stability at -196°C. The valve features an extended bonnet design that keeps the stuffing box away from the low-temperature zone, preventing packing freeze-up and valve stem seizure. The disc rotates 90 degrees to achieve both on-off control and flow regulation. Widely used in LNG receiving terminals, air separation units, low-temperature storage and transportation, and petrochemical low-temperature facilities, it is critical equipment for reliable shut-off and regulation under ultra-low temperature conditions.

DD343F Soft Seal Low Temperature Flange Butterfly Valve Product Image Product Image

DD343F Soft Seal Low Temperature Flange Butterfly Valve Features

1.  Anti-Freezing Extended Bonnet Design: The extended bonnet structure effectively lengthens the cold conduction path, keeping the stuffing box in a relatively higher temperature zone. This prevents packing freeze-up and valve stem seizure, ensuring flexible and reliable operation.

2.  Deep Cryogenic Treatment and Low-Temperature Materials: All critical components undergo deep cryogenic treatment to relieve stress. The chemical composition and low-temperature impact toughness of the materials are strictly controlled to ensure low-temperature toughness and dimensional stability at -196°C, preventing brittle fracture, deformation, and leakage at cryogenic temperatures.

3.  Reliable Sealing with Triple Eccentric Structure: The triple eccentric sealing structure ensures almost no wear between the seat and the disc, providing a "tighter-as-pressure-increases" sealing function. The sealing ring is made of stainless steel or PTFE, combining the advantages of both metal hard sealing and elastic sealing.

4.  Convenient Installation with Flanged Connection: The standard flanged connection facilitates easy installation and disassembly, allowing efficient connection with various low-temperature equipment and pipelines. It is suitable for a wide range of sizes from DN50 to DN1000.

5.  Excellent Flow Regulation Performance: The flow characteristic tends to be proportional, offering good regulation performance. Flow can be adjusted arbitrarily within the 0 to 90-degree rotation range, allowing the valve to function as both a shut-off valve and a control valve.