Flameproof valve electric device selection should pay attention to the key points of import valve selection
Key points to be paid attention to when selecting electric device of flameproof valve
When selecting the flameproof valve electric device and determining the functional requirements, the key points that need to be paid attention to include determining the IP protection level of the flameproof valve electric device, the power supply voltage of the flameproof valve electric device, the 90 running time of the flameproof valve electric device and the form of the electric actuator.
1. Determine the IP protection level of the flameproof valve electric device
In the selection of flameproof valve electric device, first of all, according to the working environment and use requirements to determine the IP protection level of flameproof valve electric device. General water supply and drainage system electric valve drive device according to the different working environment can be divided into outdoor type, indoor type. The IP protection level commonly used for outdoor electric valve drive devices is IP54 or IP55, and the IP protection level commonly used for indoor electric valve drive devices is IP43 or IP44. In general, electric valve actuation devices for water supply and drainage systems are not submersible. The IP protection level of flameproof valve electric device shall be proposed and determined by water supply and drainage professional technicians.
2. Determine the power supply voltage of the flameproof valve electric device
At present, the power supply voltages commonly used by domestic users are 380V and 24V, which should be determined according to the power supply conditions provided by the outside world.
3. Determine the 90 running time of the flameproof valve electric device
The 90 running time of the so-called flameproof valve electric device, that is, the time required for the electric valve to open and close in place, the requirements are determined by the professional manufacturers of the valve and flameproof valve electric device. The running time of conventional 90 varies from 7.5 to 30s, but it should meet the requirements of water system process. 90 The shorter the running time, the greater the motor power of flameproof valve electric device, the higher the current.
High-power water pump is usually started with light load with closed valve to reduce the current of water pump starting. The water pump outlet pipe is equipped with a check valve, electric valve, etc. Generally, the starting time of the closed valve is 10 ~ 30s. Therefore, the 90 running time of the flameproof valve electric device of the water pump outlet pipe electric valve should be consistent with the starting time of the closed valve determined by the water supply and drainage process. If the opening and closing speed of the valve is too fast, it is easy to produce water hammer phenomenon.
In industrial and mining enterprises, usually equipped with a safety tank or tower water supply accident emergency water supply system. There is also a permanent electric valve on the emergency water supply pipe. In order to ensure the safety of production, the electric valve of the accident water supply pipe requires timely opening and sensitive response. Therefore, the 90 running time of the electric device of the Chongqing valve flameproof valve should also be shortened as far as possible.
Specific selection of imported valve inlet valve valve is mainly refers to foreign brands, mainly Europe and the United States, the Japanese brands, more representative brands include Britain sent her, the force Germany LIT, Japan north jersey KITZ, the United States, a RETZ, such as valve type of products are mainly imported ball valves, import cut-off valve, import control valve, butterfly valve, import Imported pressure reducing valve, imported solenoid valve, and the caliber of the product, pressure, temperature, material, connection mode, operation mode and other parameters are many, according to the actual need
Import valve valve is mainly refers to foreign brands, mainly Europe and the United States, the Japanese brands, more representative brands include Britain sent her, the force Germany LIT, Japan north jersey KITZ, the United States, a RETZ, such as valve type of products are mainly imported ball valves, import cut-off valve, import control valve, butterfly valve, import import pressure reducing valve, imported electromagnetic valve, etc., And the caliber of the product, pressure, temperature, material, connection mode, operation mode and other parameters are many, need to choose the right valve according to the actual needs, product characteristics; In this paper, combined with the German brand German LitLIT, which has been praised by customers, the specific selection of imported valves is analyzed:
A, the characteristics of the import valve have the use of characteristics and structural characteristics
1, the use of imported valve characteristics
Use characteristics to determine the main use of the valve performance and range of use, belong to the valve use characteristics are: valve category (closed circuit valve, regulating valve, safety valve, etc.); Product type (gate valve, globe valve, butterfly valve, ball valve, etc.); The main parts of the valve (valve body, cover, stem, disc, sealing surface) material; Valve transmission mode, etc.
2. Structural characteristics
Structural characteristics determine the installation, repair, maintenance and other methods of some structural characteristics of the valve, belong to the structural characteristics of the valve structure length and overall height, and the connection form of the pipeline (flange connection, thread connection, hoop connection, external thread connection, welding end connection, etc.); The form of sealing surface (insert ring, thread ring, surfacing, spray welding, body body); Valve stem structure form (rotating rod, lifting rod), etc.
Two, the selection of valve steps
Clear valve in equipment or device use, determine the working conditions of the valve: applicable medium, working pressure, working temperature and so on; For example, if you want to choose a German Lit-LIT globe valve, confirm that the medium is steam, working principle is 1.3Mpa, working temperature is 200℃.
Determine the nominal size and connection mode of the pipe connecting with the valve: flange, thread, welding, etc.; For example, select the inlet globe valve and confirm that the connection is flanged.
Determine the way to operate the valve: manual, electric, electromagnetic, pneumatic or hydraulic, electro-hydraulic linkage, etc. For example, the choice is a manual stop valve.
According to the pipeline transmission medium, working pressure, working temperature to determine the selected valve shell and inner parts of the material: cast steel, carbon steel, stainless steel, alloy steel, stainless acid-resistant steel, gray cast iron, malleable iron, ductile iron, copper alloy, etc. For example, the globe valve choice of cast steel material.
Choose the type of valve: closed circuit valve, regulating valve, safety valve, etc.;
Determine the type of valve: gate valve, globe valve, ball valve, butterfly valve, throttle valve, safety valve, pressure reducing valve, steam trap, etc.
Determine the parameters of the valve: for the automatic valve, according to different needs to determine the allowed flow resistance, discharge capacity, back pressure, etc., and then determine the nominal diameter of the pipeline and the diameter of the seat hole;
Determine the selected geometric parameters of the valve: structure length, flange connection form and size, open and close the valve height direction of the size, the connection of the bolt hole size and number, the size of the entire valve shape;
Use AVAILABLE information: VALVE product catalog, valve product sample, etc., to select the appropriate valve product.
Three, choose the basis of the valve
The use of the selected valve, operating conditions and operating control mode;
The nature of the working medium: working pressure, working temperature, corrosion performance, whether it contains solid particles, whether the medium is toxic, whether it is flammable, explosive medium, medium viscosity, etc.; For example, want to choose Germany LIT imported solenoid valve, medium and environment flammable, explosive, generally choose explosion-proof solenoid valve; For example, to choose the German LIT ball valve, medium containing solid particles, generally to choose the V-shaped hard seal ball valve.
Requirements for valve fluid characteristics: flow resistance, discharge capacity, flow characteristics, sealing grade, etc.;
Installation size and external size requirements: nominal diameter, connection with the pipe and connection size, external size or weight limit, etc.
Reliability of valve products, explosion-proof electric device performance and service life of the additional requirements (when the selected parameters should be paid attention to: if the valve is used for control purposes, must determine the following additional parameters, operation methods, comparison, and * * small flow, normal flow pressure drop, the comparison of pressure drop and valve is closed and small inlet pressure).
According to the above selection of valve basis and steps, reasonable and correct selection of the valve must also be a detailed understanding of the internal structure of various types of valves, in order to be able to preferentially choose the valve to make a correct choice.
The ultimate control of the pipeline is the valve. Valve opening and closing parts control the flow of the medium in the pipeline, the shape of the valve flow channel makes the valve has a certain flow characteristics, in the selection of the pipeline system most suitable for the installation of the valve must take this into account.
Summary, selection of several elements: determine what function to choose the valve, confirm the temperature, pressure of the medium, confirm the flow of the valve and the need for caliber, confirm the material of the valve, operation mode;
Post time: Oct-14-2022
