Type needle valve actuating device according to the output shaft is divided into many rotary movement way, part of the rotary and linear reciprocating 3 kinds. Rotary rotary is more circle, more suitable for the stem or stem nut need revolving circle in order to fully open or close the valve, such as gate valve, globe valve, the output torque value of series of 40 ~ 10000), commonly (thrust is 20 ~ 1.1 million cows). Part of rotary is suitable for the stem within a circle in the rotation can be fully open or close the valve, such as ball valve, butterfly valve, the output torque of the series is generally 125 ~ 125000). Linear reciprocating applicable to stem only do needle valve manufacturer linear reciprocating motion can be fully open or close the valve, such as solenoid valve.
Import needle valve can be divided into stainless steel valve, valve and chrome molybdenum steel carbon steel needle valve type. Usually, and USES the form of the structure to have commonly: thread the needle valve, ferrule needle valve type valve, flange, welding needle valve, the Angle of needle valve, pressure gauge three-way valve type valve, level gauge, the Duo function needle valve, pressure meter hand type sampling valve, needle valve, etc.
Instrument valve group usually has two valves, three valves group and five valve group. Instrument valve in the pipe system measuring instrument to open and close pipe channel. Due to fire, explosion, high pressure resistance and excellent sealing performance, it is a power plant, oil refineries, chemical plants and equipment to measure important products in the pipeline. Type needle valve is typically used for simple measurement in the pipeline, and instrumentation valve group is used for more complex in the pipeline for separation and merger.
Nickel base corrosion resistance and promote the type valve of the main elements are as follows:
Copper, chromium, molybdenum. With good comprehensive performance, can be all kinds of acid corrosion and stress corrosion resistance. Early application of nickel copper alloy, also called monel alloy; Chromium and nickel alloy, nickel molybdenum alloy, nickel chromium molybdenum alloy, etc. Used in the manufacture of all kinds of corrosion resistant parts.
Nickel base type corrosion resistance and promote the main valve is chromium, molybdenum and tungsten alloy element, also contains a small amount of niobium, tantalum, and indium. Besides with mo resistance, its Yang resistance, corrosion resistance, weldability. Also can produce mo resistance components, also can be used as coating material, by overlaying welding and spraying process be coated on the surface the other substrate materials.
Type stainless steel needle valve is whole process material 304316321201 stainless steel forging processing production of needle valve, brass is made by a brass alloy casting process of needle valve. Stainless steel corrosion resistance, resistance to high pressure, high temperature resistant, high cleanliness, a lot of advantages. The brass or copper materials do not have the 12 needle valve advantages of resistance to high pressure, high temperature resistant, relative to the stainless steel needle valve as many, the scope of use stainless steel needle valve is widely used.
Type stainless steel needle valve and instrumentation valve body and internal parts are all materials with solid or forging bar solid body directly, high density, tensile performance is strong, adopts CNC precision machining, precision degree is high, good seal. Brass type needle valve, and the process for forging brass instrument valve casting body, low tensile performance, corrosion resistance is poor, not suitable for high temperature and high pressure, bad working conditions, such only suitable for use in water heating, air conditioning and other devices.