The characteristics of electric valve process structure analysis valve process liquid function and design scheme

The characteristics of electric valve process structure analysis valve process liquid function and design scheme

Electric valve position torque is larger than the general valve, electric valve power switch speed can be adjusted, compact structure, easy maintenance, the whole process of the posture because of its own cache characteristics, not easy to damage due to stuck, but there must be pneumatic valves, and its automatic control system is more complicated than electric valve.
This type of valve in the pipeline should generally level assembly.
In general, what is the most basic maintenance method of overload: overload protection for continuous operation or start operation of the motor, the selection of temperature controller; For the maintenance of motor turns, choose heat relay; For short circuit fault safety accident, choose circuit breaker or over current solenoid valve.
Electric valve position torque is larger than the general valve, electric valve power switch speed can be adjusted, compact structure, easy maintenance, the whole process of the posture because of its own cache characteristics, not easy to damage due to stuck, but there must be pneumatic valves, and its automatic control system is more complicated than electric valve.
This type of valve in the pipeline should generally level assembly. Electric regulating valve is generally composed of electric actuator and valve. Electric regulator uses electromagnetic energy as the driving force to drive the valve according to the electric actuator, and completes the power switch position of the valve.
To achieve the target of the pipeline medium power switch. So, electric valve in the installation process what aspects need to pay attention to /p> Electric valve device is to promote valve program control, automatic control and remote control indispensable machine equipment, its movement can be adjusted by travel arrangement, rotation or radial thrust size. Because the working characteristics and utilization rate of the electric valve device lies in the type of valve, the working system of the device and the position of the valve in the pipeline or equipment, the correct selection of the electric valve device is particularly important to avoid the occurrence of overload condition (the working transfer distance is higher than the operating rotation).
In general, the correct selection of electric valve device is an important basis for the following: operating torque operating torque is the most basic parameters of the selection of electric valve device, electric device derived torque should be 1.2 ~ 1.5 times of the actual operation of the valve torque.
The main structure of the actual operation of the thrust electric valve device is mainly divided into two kinds: one is not equipped with the thrust disc, and the torque is immediately derived; The other is equipped with a thrust disc and the derived torque is converted to derived thrust according to the stem nut in the thrust disc.
The number of turns of input shaft rotation of electric valve device is more or less related to the nominal diameter of the valve, seat distance and the number of screws. It should be calculated according to M=H/ZS (M is the total number of turns of rotation that the electric device should meet, H is the relative height of valve opening, S is the screw pitch of the valve seat drive system, and Z is the number of screws of the valve seat). Seat aperture for a multi-rotating open-rod valve, an electric valve cannot be installed if the electric device allows the requested very large seat aperture to not pass through the valve seat.
Therefore, the nominal diameter of the hollow input shaft of the electric device must exceed the valve seat diameter of the open rod valve.
For some rotary valves and open-rod valves in multi-rotary valves, although there is no need to worry about the problem of valve seat diameter, the valve seat aperture and groove size should also be taken into account in the selection of assembly, so as to enable normal operation after assembly.
If the exported speed is too fast than the valve switching speed, it is easy to produce water percussion phenomenon.
Therefore, should be based on different range of application, select the appropriate opening and closing speed. Electric valve devices have a special requirement that they can limit the turn or radial force.
Generally, electric valve devices use couplings with limited rotations.
When the specification of the electric device is clear, its control rotation may be confirmed.
Generally in the pre-determined time operation, the motor is not easy to overload.
However, overload may be caused if the following conditions occur: first, the power supply current is low, unable to get the required rotation, so that the motor stops rotating; Second, the torque limit organization is incorrectly adjusted, so that it exceeds the stop of the rotation, resulting in continuous too large rotation, so that the motor stops running; Three is intermittent application, the heat deposit, more than the motor allowable temperature increase; Fourth, for various reasons, the torque limit organization power supply circuit failure, so that the rotation is too large; Fifth, the temperature of the use scene is too high, and the relativity reduces the thermal conductivity of the motor. In the past, the protection method of the motor is the application of circuit breaker, over current solenoid valve, heat relay, temperature controller, but these methods have their own advantages.
There is no reliable maintenance method for variable load machines such as electric devices.
Therefore, a variety of arrangements must be taken, specifically there are two main: one is to judge the adjustment of the motor input current; The second is to judge the burning condition of the motor itself.
Both ways, regardless of the class will take into account the thermal conductivity of the motor for a given duration capacity.
In general, what is the most basic maintenance method of overload: overload protection for continuous operation or start operation of the motor, the selection of temperature controller; For the maintenance of motor turns, choose heat relay; For short circuit fault safety accident, choose circuit breaker or over current solenoid valve.
Features of valve process Liquid function and design scheme Check valves * Allow liquid to flow in the desired direction. The design scheme is such that all mobility or working pressure in the opposite direction is caused by rigid restrictions. Every throttle valve is a check valve.
Double-position (open-close) valve, which has the effect of controlling freight logistics closing and allowing the basis; Pressure regulating valve is a common end control component.
The term end-control unit refers to a stable machine device that requires increased power and precision to control a fluid material to a desired standard of motion.
one According to the solution of the process liquid function and design characteristics of the program 1, check valve check valve * allow liquid in the expected direction of liquidity. The design scheme is such that all mobility or working pressure in the opposite direction is caused by rigid restrictions. Every throttle valve is a check valve.
Check valves are used to prevent fluid backflow, which can damage equipment and disrupt process flow.
When the pump or refrigeration compressor is out of production, this type of valve is very useful for the safety of the liquid operation of the pump or refrigerant compressor operating reflux.
Check valves are also used in processes with different working pressures that are to be kept separate.
2, the valve can be divided into three types: double-position (open-close) valve, which has the effect of controlling the closure of freight logistics and allowing the basis; Check valve, it can only freight logistics in one direction fitness exercise; The relief valve, which can be opened to fully closed at any point to regulate freight flow. One disorder defined by function is that special oil circuit plate designs, such as stop valves, stop valves, plug valves, gate valves, disc valves and rubber hose valves can be classified into one, two or all three categories. For example, the plug valve is suitable for open – close dual practical operation, and the addition of actuators, can be used as a throttle valve pressure regulating valve.
Another example is the spherical valve body, which, according to its internal design scheme, can be an open – close double position valve, a check valve or an overflow valve.
So when the unique valve types and other special classification as equal at the same time, the customer should be concerned.
3. The pressure regulating valve of the end control component in the control ring road is the most common end control component.
The term end-control unit refers to a stable machine device that requires increased power and precision to control a fluid material to a desired standard of motion.
Other control components include dosing pumps, blinds, shock absorbers, wild pitch blades, and flow control devices.
As the end control component, the pressure regulating valve is a part of the ring road. It is generally composed of two other components in addition to the pressure regulating valve: the sensor component and the operator.
Sensor components (inductors) accurately measure actual process parameters, such as liquid pressure, level gauges, or ambient temperature.
The sensor component uses a transmitter to transmit a line containing process parameter data to a manipulator or a larger dispatch automatic control system.
The manipulator receives input from the sensor and compares it with the desired value at the set point and process position.
At the more specific point of setting, the manipulator makes all necessary adjustments to the process by transmitting a signal to the final control unit (presumably not the pressure regulating valve). The valve changes in accordance with a data signal sent from the manipulator, which is detected and verified by the sensor element.
Figure 1.8 shows a general ring road data diagram using step (FT), working pressure (PT), and temperature (TT) transmitters and pressure regulator and operator connections.
4, double valve (open – close valve) sometimes refers to the partition valve, double valve is mainly used to start or stop the material flow according to the process.
General double-position valve includes globe valve, plug valve, gate valve, pressure reducing valve and cylinder pump bottom valve.
Most two-position globe valves are made by hand, but the addition of an actuator allows automatic operation.
Two-position valves are commonly used for freight logistics to be diverted around an area where maintenance is carried out or where workers must be safe from hidden safety hazards.
They are also of primary use for mixtures, where much of the freight flow is mixed within a predetermined moderate period and no precise metrological verification is required.
The intelligent management system also requires automatic two-position valves that close immediately when an emergency occurs.
The reducing valve is a self-actuated two-position valve that opens when the pressure is exceeded in advance. There are two kinds of valves: pressure relief valves and valves.
Reducing valve is mainly used for safety protection liquid actual operation too much increase; Valve is mainly used for the actual operation of steam body, here the system software is too much increased safety and process damage and must empty themselves.
5, relief valve throttle valve is mainly used to adjust the total flow rate in operation, ambient temperature or pressure.
The valve can be arranged from the valve travel within all parts of the theme activity and fixed in the part, including opening or closing parts.
Therefore, it can also be used as a two-position valve.
However, many relief valves are equipped with hand-operated spines and support rods, and some are equipped with actuators and actuator system software for greater thrust, transposition, and automatic control systems.
A pressure regulator is a relief valve that changes the position of the valve to maintain the stable pressure produced in the middle and downstream. If the working pressure rises in the middle and downstream manufacturing, the controller is turned off slightly to reduce the working pressure. If the middle and downstream manufacturing working pressure is reduced, the controller is opened to increase the pressure.
Part of the relief valve family is an automatic control valve, sometimes called a pressure regulating valve, which is a technical term for a valve, which changes the flow standard to fit the process standard.
The valve is always equipped with an actuator for automatic control.
The actuator is designed to receive a command data signal and switch to an actual valve position through an external power device (gas, electricity, or hydraulic press) to meet the functional requirements of the exact time.