The type and selection principle of chemical pneumatic valves

chemical type pneumatic valve and selection principle of
chemical pneumatic valve is one of the important chemical piping control medium flow accessories, detailed principle and structure of the sectional view with reference to the relevant information books, pneumatic valve, pneumatic valve by pneumatic valve body, opening and closing of cover three parts.
chemical pneumatic valves.
, opening and closing action - — Cut off or communication pipe fluid flow;
and regulating role - — Adjust the flow rate, flow velocity;
and throttling action - — After making the fluid through the pneumatic valve produces a lot of pressure drop;
and other role - — 一个。 Automatic opening and closing b. To maintain a certain pressure c. Vapor barrier drainage.
chemical type pneumatic valve:
, according to utility cent: truncation pneumatic valve, regulating valve, pneumatic valve, check valve pneumatic valve, pneumatic valve safety;
, according to the force points: his action with pneumatic valve, automatic pneumatic valves.
chemical pneumatic valve not only involves a wide range of application of request higher than ordinary pneumatic valve, pneumatic valve used in chemical industry more vulnerable to corrosion. Used in different chemical industry the requirement of pneumatic valve is different also, such as large-scale petrochemical enterprises and chlor-alkali industry, in the pneumatic valve of high temperature, high pressure resistance, wear resistance, pressure and other conditions have very big difference. So on chemical industry selection and use of pneumatic valve is very dangerous, must be strictly implemented according to the standards such as chemical. Chemical special pneumatic valves for ordinary pneumatic valve manufacturing specification is more stringent, in the face of complex industrial systems and diversity of pneumatic valve. To choose the right pneumatic valves are used in different industrial pipeline fluid flow control system, and should know the various performance and applicable range of pneumatic valves, and to select the corresponding pneumatic valve used in the system should be familiar with the operation of the pneumatic valve specification and matters needing attention, and to follow the principle of pneumatic valve in chemical, strictly control the quality of pneumatic valve.
chemical principles in the selection of pneumatic valves:
are usually used in pneumatic valves are straight through for the chemical industry, small flow resistance. Usually selected as the medium of globe and adjust control flow with chemical pneumatic valve, common are as pneumatic pneumatic valve, ball valve, gate valve, pneumatic safety valve, cock pneumatic pneumatic valve, butterfly valve, check valve, etc. Pneumatic ball valve and plug of diversion of pneumatic valve suitable for medium, brake pneumatic valves are best suited for medium with suspended particulate matter. Chemical pneumatic valve body material is usually cast steel WCB, and stainless steel material, the seals have alloy steel and ptfe. General non-corrosive medium often choose pneumatic valve body cast steel, rubber or ptfe, weak corrosive aerodynamic body can choose stainless steel material, sealing for ptfe, strong corrosive pneumatic valve body should choose L stainless steel material, ptfe sealing to enhance, high temperature medium to choose hard seal cast steel material, high pressure pipe should choose forging pneumatic valves, etc. ( Specific selection please inquire to the suppliers, will be subject to the actual selection) 。
chemical pneumatic valve connection mode:
industrial chemical pneumatic valve connection mode can be divided into: connect flange, silk mouth, welding and connection to the clamp. Attention:



inspection before using the project include:
and pneumatic valve inside and outside surface defects such as sand holes, cracks;
and pneumatic seat and aerodynamic body joint is rigid, it fits the pneumatic valve seat, pneumatic valve core sealing surface with and without defects;
, pneumatic valve rod connected to the pneumatic valve core is flexible and reliable, pneumatic valve stem is bent, thread is damaged, corrosion;
, whether the packing and gaskets aging damage;
, pneumatic valves open and flexible. Common problem:

, and pipeline connection flange, thread leak;
and stuffing box leakage, waist cushion leakage and pneumatic valve stem to open fixed;
the seat closed is lax, pneumatic valve core and pneumatic form internal leakage.