Low-load butterfly valve for ventilation or gas conveyance

1. Introduction to On-site Application Conditions

Low-load butterfly valves are used in the metallurgical industry for ventilation or gas transmission in blast furnace gas, compressed air transmission, flue gas dust removal systems, and sintering electric furnaces, preheating furnaces, and insulation furnaces. This valve needs to meet the functions of cutting off, regulating, and switching the fluid. Some gases are high-temperature, and conventional soft-sealed valves are not suitable due to limitations of rubber or plastic parts. Metal hard-sealed valves are expensive and too heavy for convenient use. Therefore, low-load butterfly valves are particularly suitable for ventilation valves in this low-pressure system.

Low-load butterfly valves are mainly suitable for controlling the flow and pressure of low-pressure media. They have the characteristics of simple structure, convenient operation, and light weight, and are usually used for automatic control and remote control in the petroleum, chemical, metallurgical, power station, and light industry industries.

2. Challenges and Problems Faced

1. The media pressure in these systems is generally low, mostly in the Kpa level, so the pipeline design is generally thinner and prioritizes weight bearing. Therefore, it is hoped that the valve body design can be as light as possible while meeting the pressure requirements;

2. The structural length of the valve is not standardized, and each manufacturer has its own design parameters. When replacing spare parts, the valve structure length needs to be flexible to meet installation requirements;

3. These valves generally do not have high sealing requirements, but some locations have stricter sealing requirements, so the sealing structure needs to be flexible;

4. High-temperature conditions need to consider valve heat dissipation;

5. Flue gas conditions need to consider the influence of particle adhesion or scaling.

EICMATION's Recommended Solution

1. To consider the lightweight valve body, the heavy casting body is eliminated, and a full-welded structure is used instead. The wall thickness can be flexibly adjusted according to the operating pressure;

2. Because it is a full-welded valve body, the structural length can be flexibly changed according to different requirements, and customized spare part replacement can be achieved;

3. To adapt to different operating conditions, there are three types of seals available: open type, back seat type, and sealed type, including:

The open type is suitable for conditions where the medium is prone to particle adhesion or scaling, which can effectively prevent valve jamming;

The back seat type is suitable for most ventilation systems, and the sealing is better than the open type;

The sealed type is suitable for places with slightly higher sealing requirements. This type of butterfly plate can add rubber or glass fiber auxiliary seals, and the sealing performance is greatly improved compared to the back seat type.

4. The welded bracket can adapt to high-temperature structures for increased heat dissipation;

5. For operating conditions with severe internal cavity adhesion, an open structure can be used, with a reinforced butterfly plate and a toothed cutout on the outer circle of the butterfly plate to scrape off the attached material.