Classification of butterfly valves by connection mode?

1. Wafer butterfly valve

The butterfly plate of the double clip butterfly valve is installed in the diameter direction of the pipe. The valve is fully open.

The butterfly valve has the advantages of simple structure, small volume and light weight. Butterfly valve has elastic seal and metal seal. Elastic sealing valve, sealing ring can be inlaid on the valve body or attached to the periphery of butterfly plate.

2. Flange butterfly valve

The flange type butterfly valve is vertical plate structure, and the valve stem is the sealing ring of integral metal hard sealing valve

It is a composite structure of flexible graphite plate and stainless steel plate, which is installed on the valve body, and the sealing surface of butterfly plate is overlaid with stainless steel. The sealing ring of soft sealing valve is made of nitrile rubber and is installed on the butterfly plate.

3. Lug type butterfly valve

4. Welded butterfly valve

Welded butterfly valve is a kind of non airtight butterfly valve, which is widely used in pipes with medium temperature ≤ 300 ℃ and nominal pressure of 0.1MPa in the production process of building materials, metallurgy, mining, electric power, etc., to connect, open and close or adjust medium quality.

Electric control butterfly valve belongs to a variety of electric valve and electric control valve. The main connection methods are flange type and clamp type, which are important executive units in the field of industrial automation control. There are two main points for the installation of electric regulating butterfly valve: the installation position, height, inlet and outlet direction must meet the design requirements, the direction of medium flow should be consistent with the arrow direction marked on the valve body, and the connection should be firm and tight. Before the installation of the electric control butterfly valve, the appearance inspection must be carried out, and the valve name plate shall comply with the provisions of the current national standard general valve marking (GB 12220). For valves with working pressure greater than 1.0MPa and cut off on main pipe, strength and tightness test shall be conducted before installation. It can be used only after it is qualified. In the strength test, the test pressure is 1.5 times of the nominal pressure, and the duration is not less than 5min. The valve shell and packing are qualified if there is no leakage. The electric regulating butterfly valve can be divided into offset plate type, vertical plate type, inclined plate type and lever type according to the structural form; it can be divided into soft sealing type and hard sealing type according to the sealing form; the soft sealing type generally adopts rubber ring sealing, while the hard sealing type usually adopts metal ring sealing.

Functional use

When the butterfly valve is fully opened to fully closed, it is usually less than 90 ° and the butterfly valve and butterfly rod have no self-locking ability. In order to locate the butterfly plate, worm gear reducer should be installed on the valve rod. The use of worm gear reducer can not only make the butterfly plate have self-locking ability, make the butterfly plate stop at any position, but also improve the operation performance of the valve. Industrial butterfly valve features: high temperature resistance, high pressure range, large nominal diameter, carbon steel valve body, metal ring instead of rubber ring. Large high temperature butterfly valve is made of steel plate welding, which is mainly used for flue gas duct and gas pipeline with high temperature medium.