Pneumatic valve with special material corrugated pipe material requirements

in the metal corrugated pipe pneumatic valve, metal bellows component in the pneumatic valve stem and valve body between the process fluid provides the axial movement of metal shell, form a dynamic seal. Bellows under pneumatic compression and stretching of the stem under medium pressure, temperature and corrosion at the same time, to ensure that the pneumatic valve for zero leakage in life cycle. With the common application of corrugated pipe in pneumatic valve industry, technical requirements of corrugated pipe is increasing constantly. Pneumatic valves with metal corrugated pipe resistance to high pressure, high temperature resistant, corrosion resistance and long life direction. Pneumatic valve basic requirements with corrugated pipe materials must be suitable for the production of corrugated pipe material has good plasticity, high elastic limit, tensile strength and fatigue strength, good welding performance, stability of elastic properties. Austenitic stainless steel for with these performance characteristics, widely used in the manufacture of bellows. Resistance to high pressure is the basic requirement of pneumatic valves and corrugated pipe, but with the increase of pneumatic valve pressure rating, corrugated pipe wall thickness and stiffness increased, to the pneumatic valve opens and corrugated pipe manufacturing is more difficult. Corrugated pipe production factory is generally not simply increase the wall thickness, but by adding layer method to improve the product resistance to pressure, at the same time reduces the axial stiffness of the bellows, decrease the pneumatic valve opening force. The nominal pressure (MPa Lb the following range of austenitic stainless steel corrugated pipe wall thickness is commonly. ~。 Mm, layer to layer. The stress level of corrugated pipe has a certain generality, has formed a series of products. When the stress reaches the MPa ( Lb above, according to the pneumatic valve diameter and working temperature, choosing the appropriate material manufactured by the specialized manufacturer of corrugated pipe design. Corrosion resistant non-metal material corrosion resistant performance is good, fluorine plastic anticorrosive pneumatic valve is widely used, four fluorine pneumatic valve bellows have some application field. But for nonmetallic material strength and heat resistance are low, generally use temperature not to exceed ℃, application scope is limited. Represented by, L austenitic stainless steel can handle corrosive weaker condition, but in the fight against chlor-alkail industry such as wet chlorine corrosion and other harsh corrosive conditions, must adopt excellent corrosion resistance of the corrosion resistance of alloy materials. Corrosion resistant alloy's resistance to pitting and crevice corrosion ability common point corrosion equivalent ( PRE value representation, PRE value according to the type ( Calculation. = % Cr +。 ××% N %莫+ ( The higher values of the PRE, critical crevice corrosion temperature of the alloy ( CCTS and critical pitting temperature ( The higher the CPT. From the table as you can see, several corrosion resistant alloy PRE value and L PRE value is much higher. Table and pitting on the mechanical properties of the equivalent materials