Chimney valve

Chimney valves (also known as flue gas valves) are key equipment used in industrial pipeline systems to control the flow of media such as flue gas and coal gas. According to application scenarios and technical characteristics, they can be divided into the following categories:
1、 Core functions and structural characteristics
Media control
Mainly used for the flue, gas, and air pipelines of blast furnace hot blast stove systems, achieving airflow cut-off and working condition switching, supporting electric, hydraulic, or chain transmission modes. The valve body is usually made of cast steel material, and the sealing surface is welded with hard alloy to adapt to high temperature and high pressure environments.
Sealing technology
Traditional valves used to leak due to low sealing bandwidth and cooling efficiency. After improvement, O-ring seals were used instead of asbestos gaskets, and the leakage rate was controlled within 0.5% through labyrinth metal seals and stepped boss structures. Some models are equipped with hydraulic telescopic rods and magnetic seals to enhance sealing.
2、 Classification and Applicable Scenarios
Disc type flue valve
The angular valve body is connected to the flue, and the valve cover is stably opened and closed through a balance weight, suitable for working conditions with temperatures below 500 ℃. During design, a large clearance (>1mm) should be reserved for the transmission shaft to prevent thermal deformation and jamming.
Electric flue valve
Adopting an upper mounted structure, reducing the number of valve body connecting bolts, and improving reliability under high-pressure and large-diameter working conditions. The nominal pressure covers PN 10-16MPa, with a diameter range of DN50-DN300mm, suitable for fields such as coal chemical industry and thermal power generation.
High temperature butterfly valve
The DN2200 butterfly valve with a temperature resistance of 800 ℃ adopts a vertical plate structure and is equipped with electric drive, suitable for high-temperature dust and gas environments. Some models have solved the problem of thermal deformation and leakage by modifying the four-bar linkage structure.
3、 Industry Applications and Standards
Metallurgy and Energy: Used for switching combustion and air supply conditions in blast furnace hot blast stove systems, the "ultra-high temperature flue valve" group standard launched in 2025 will further standardize its application quality.
Environmental Protection and Chemical Industry: To achieve medium separation in scenarios such as waste incineration and cement waste heat power generation, it is necessary to conduct tests such as air leakage and fire resistance, and comply with standards such as GB/T 13927-2018.
4、 Selection and maintenance suggestions
In the civilian field, kitchen check valves can be designed with full sealing and odor prevention (such as submarine F160), and attention should be paid to fire and rodent bite prevention functions.
Industrial maintenance: In response to the leakage problem of flue gas butterfly valves, the four-bar linkage sealing renovation plan is prioritized to solve the sealing failure caused by high temperature deformation and particle wear from a structural perspective

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