Time：2016-04-13 19:33:45 Views：
In fluid piping systems, valves to control the device, its main role is to isolate equipment and pipeline systems, regulating traffic, preventing the return of the pressure regulation and excretion. Because the pipeline system to select the most suitable valve is very important, therefore, to understand the characteristics of the valve and valve selection and the basis becomes crucial step up.
Valve industry so far has been able to produce the full range of gate valve, globe valve, throttle valve, plug valve, ball valve, electric valve, diaphragm valve, check valve, safety valve, reducing valve, steam trap and emergency shut-off valve in 12 categories, more than 3,000 models, more than 4000 specifications of valve products; maximum working pressure of 600MPa, the largest nominal diameter up to 5350mm, maximum working temperature of 1200 ℃, the minimum operating temperature of -196 ℃, It is used to water, steam, oil, natural gas, strong corrosive media (such as concentrated nitric acid, sulfuric acid concentration, etc.), flammable medium (such as benzene, ethylene, etc.), toxic media (such as hydrogen sulfide), explosive media and radioactive medium (sodium, - loop pure water, etc.). Pressure Parts Material bronze valve, cast iron, ductile iron, high silicon cast iron, cast steel, forged steel, high, low-alloy steel, stainless and acid resistant steel, Hastelloy, Inconel Seoul, Monel, Duplex stainless steel, titanium alloy. And can produce all kinds of electric, pneumatic, hydraulic valve actuator. Faced with such a large number of valves of various species and such a complex condition, pipeline system to select the most suitable products to install the valve, I think, first of all should understand the characteristics of the valve; second choice should be to master the steps and Yi Ju valve ; What should follow the principle of selection valve.
There are two general characteristics of the valve, use and structural properties
Use the feature: it identifies the main valve performance and scope, are valves used features are: the type of valve (closed valves, regulating valves, safety valves, etc.); product type (valve, valves, butterfly valves, ball valves, solenoid valves, etc.); valve main parts (body, bonnet, stem, disc, sealing surface) of the material; valve drive pattern.
Structural features: It identifies the valve installation, repair, maintenance and other methods some of the structural characteristics, there are structural features: the structure of the valve length and overall height, form the connection with the pipe (flange connection, threaded connection, folder hoop connection, external threaded connection, welded end connections, etc.); sealing surface of the form (Ring of, thread ring, welding, spray welding, valve body); stem structure (rotation pole, lifting rod) and so on.
Select Valve steps and according to generally as follows:
⑴ selection procedure
① clear the valve in the use of equipment or device to determine the valve's working conditions: for medium, working pressure, temperature and so on.
② connection with the valve to determine the nominal pipe diameter and connections: flanges, threaded, and welding.
③ way to determine the valve operation: manual, electric, electromagnetic, pneumatic or hydraulic, electrical or electro-hydraulic linkage, etc. linkage.
④ According to a pipeline to transport the media, working pressure, working temperature to determine the valve housing and within the selected pieces of material: gray iron, malleable iron, ductile iron, carbon steel, alloy steel, stainless and acid resistant steel, copper alloy.
⑤ Select the type of valve: closed valves, regulating valves, safety valves.
⑥ determine the type of valve: gate valve, globe valve, ball valve, butterfly valve, throttle valve, safety valve, relief valve, steam trap, and so on.
⑦ determine the parameters of the valve: the automatic valve, depending on need to determine the flow resistance to allow the discharge capacity, back pressure, etc., and then determine the nominal pipe diameter and the valve seat hole diameter.
⑧ valve used to determine the geometric parameters: the length structure, form and size of flange connection, a high degree of opening and closing direction after the valve size, connection size and number of bolt holes, the valve shape size.
⑨ use of existing information: valve product catalog, product samples, and choosing the right valve of valve products.