"Honeywell (Honeywell) Valve" is a butt-type hard sealed butterfly valve for opening and closing with a circular disc with the stem pieces and turn to open, close and adjust the fluid channel of a valve. Butterfly not only simple in structure, small size, light weight, material consumption province, installation size, small, and the driving torque is small, simple, rapid, and also at the same time has a good flow regulation and close the sealing characteristics, medium and large caliber, The use of low pressure areas, butterfly valve is the dominant form. As the synthetic rubber and Teflon corrosion applications, improved performance butterfly valve, and to meet different working conditions. Over the last decade, the rapid development of the metal sealing butterfly valve with high temperature, low temperature, resistant to corrosion, high erosion resistance, high strength alloy materials in the butterfly valve in the application of the metal sealing butterfly valve in the high-temperature, low temperature, Strong erosion and other working conditions are widely used, and partially replaced the cut-off valves, gate valves and ball valves. Butterfly valve plate for the occasion with a wipe of the movement, so most of the butterfly valve can be used with suspended solid particles of the medium, based on the strength of seals can also be used in powder and granular media. Valve length and overall height of the structure of small, open and close fast, in a fully open, with a small fluid resistance, when opened to approximately between 15 ° to 70 ° when the flow control can be sensitive, butterfly structure principle is best suited for production of large diameter valves. In the following working conditions, the recommended use butterfly: ① requirements throttle, regulation and control flow; ② slurry medium and medium containing solid particles; ③ asked where the shortest length of the valve structure; ④ opening and closing speed of the occasion required; ⑤ pressure smaller occasions. In the double-digit adjusted, reduced channel, low noise, there is the phenomenon of cavitation and gasification, a small amount of leakage to the atmosphere, there are abrasive media, you can use butterfly. In the special working conditions or requirements under throttle sealed strict, or severe wear, low temperature (cryogenic) and other working conditions when using the butterfly valve, use a specially designed metal seal with three eccentric adjustment device or a special double eccentric butterfly. Soft seal butterfly valve for opening and closing the ventilation and dust-way pipeline regulation, metallurgy, light industry, power, petrochemical and gas pipeline systems and other waterways. Metal to metal sealing double eccentric butterfly valve for heating, steam, water and gas, oil, acid and alkali lines, as a regulator and the closure device. Metal to metal sealing butterfly valve face except for large swing adsorption gas separation valves, but also widely used in petroleum, chemical, metallurgy, electric power, food, medicine, water, gas transportation and other fields. Structural characteristics of butterfly has a simple structure, small size, light weight, material consumption province, installation size, small, fast switching, 90 ° reciprocating rotation, torque and other small features, for the truncated, connected, adjust the line of medium , has a good flow control characteristics and close sealing performance. The streamlined design of the disc, the fluid resistance loss is small, can be described as an energy-efficient products. Stem to pass pole structure, after quenching, with good mechanical properties and corrosion resistance, scratch resistance. Butterfly valves open and close only when the stem rotates without lifting operation, easy to damage the stem packing, sealing and reliable. And disc cone off of fixed, extended end to prevent out of design, in order to avoid the junction of stem and disc stem fracture collapse of the accident. Connections are flanged, wafer, welded connections and lug wafer. Drive the form of a manual, worm gear drive, pneumatic, hydraulic, electric, electro-hydraulic actuator linkage, etc., can realize remote control and automation. Butterfly valve pressure test method for the model