I. Product Overview

Butterfly valves, also known as rotary valves, are simple regulating valves used for on-off control of low-pressure pipeline media. A butterfly valve is a valve in which the closing member (valve disc or butterfly plate) is a disc that rotates around a valve shaft to achieve opening and closing.

The valve can be used to control the flow of various types of fluids, including air, water, steam, various corrosive media, slurries, oils, liquid metals, and radioactive media. In pipelines, it mainly plays a role in cut-off and throttling. The butterfly valve's closing member is a disc-shaped butterfly plate that rotates around its own axis within the valve body to achieve opening or regulating purposes.

II. Butterfly Valve Structure

It mainly consists of a valve body, valve stem, butterfly plate, and sealing ring. The valve body is cylindrical, with a short axial length and a built-in butterfly plate.

III. Butterfly Valve Characteristics

1. Butterfly valves have characteristics such as simple structure, small size, light weight, low material consumption, small installation dimensions, rapid switching, 90° reciprocating rotation, and small driving torque. They are used to shut off, connect, and regulate media in pipelines, possessing good fluid control characteristics and sealing performance.

2. Butterfly valves can transport slurries and accumulate minimal liquid at the pipe mouth. Under low pressure, good sealing can be achieved. They also have good regulating performance.

3. The streamlined design of the butterfly plate results in low fluid resistance loss, making it an energy-saving product.

4. The valve stem has a through-stem structure, is subjected to quenching treatment, and has good comprehensive mechanical properties and corrosion resistance, as well as scratch resistance. When the butterfly valve opens and closes, the valve stem only rotates without vertical movement, the valve stem packing is not easily damaged, and the seal is reliable. Fixed to the butterfly plate cone pin, the outward end is designed to prevent ejection, preventing the valve stem from bursting out in case of accidental breakage at the connection between the valve stem and butterfly plate.

5. Connection methods include flange connection, wafer connection, butt welding connection, and lug wafer connection.

Drive types include manual, worm gear drive, electric, pneumatic, hydraulic, and electro-hydraulic actuators, allowing for remote control and automated operation.

IV. Main Classifications

Classified by drive type:

(1) Electric butterfly valve (2) Pneumatic butterfly valve (3) Hydraulic butterfly valve (4) Manual butterfly valve

Classified by structural type:

(1) Center sealed butterfly valve

(2) Single eccentric sealed butterfly valve

(3) Double eccentric sealed butterfly valve

(4) Triple eccentric sealed butterfly valve

Classified by connection method:

1. Wafer butterfly valve

The butterfly plate of a wafer butterfly valve is installed in the diameter direction of the pipe. The valve is in a fully open state.

Wafer butterfly valves are simple in structure, small in size, and light in weight. Butterfly valves come in two sealing types: elastic sealing and metal sealing. For elastic sealing valves, the sealing ring can be embedded in the valve body or attached to the periphery of the butterfly plate.

2. Flanged butterfly valve

Flanged butterfly valves have a vertical plate structure, and the valve stem is an integral metal hard seal valve. The sealing ring

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

3. Lug butterfly valve

4. Welded butterfly valve

A welded butterfly valve is a non-sealed butterfly valve widely used in pipelines with a medium temperature ≤300℃ and a nominal pressure of 0.1Mpa in the production processes of building materials, metallurgy, mining, and power generation, used for connecting, opening, closing, or regulating the flow of media.