The role of solenoid valve, thermal expansion valve, four-way valve, gate valve, butterfly valve
An electromagnetic valve is an electromagnetically controlled industrial device that is an automated basic element for controlling fluids. It is an actuator and is not limited to hydraulic and pneumatic. It is used to adjust the direction, flow rate, speed and other parameters of the media in the industrial control system. Solenoid valves can be combined with different circuits to achieve the desired control, and the control accuracy and flexibility can be guaranteed. There are many kinds of solenoid valves. Different solenoid valves play a role in different positions of the control system. The most commonly used ones are check valves, safety valves, directional control valves, and speed control valves.
The thermal expansion valve controls the flow of refrigerant into the evaporator by controlling the superheat of the gaseous refrigerant at the outlet of the evaporator. The thermal expansion valve realizes the throttling of the condensing pressure to the evaporating pressure, and controls the flow of the refrigerant at the same time; its volume is small, but its function is huge, and its work is good or bad, directly determines the working quality of the entire system and is given in the best way. The evaporator supplies liquid to ensure that the superheat of the refrigerant vapor at the outlet of the evaporator is stable, and the temperature sensing package must be in good contact with the suction pipe of the compressor to accurately sense the suction temperature of the compressor, and is usually filled with the inside of the refrigeration system. The same refrigerant, so as to realize the pressure returned through the temperature sensing package, is the saturation pressure of the refrigerant corresponding to the suction temperature of the compressor, and the expansion valve ensures that the operating environment changes (for example, the heat load changes). In order to achieve the optimal and optimal liquid supply method for the evaporator, the charge quantity of the temperature-sensing package is only corrected according to the complete evaporation of the liquid refrigerant in the completely temperature-sensing package at a certain temperature, which is equal to the effect. The pressure returned by the temperature sensing pack above the expansion valve diaphragm defines an upper limit, because if the wall surface temperature continues to increase, it will only increase the temperature inside the temperature envelope. Temperature state of the refrigerant (overheated), the pressure does not change substantially.
Four-way valve, hydraulic valve terminology, is a control valve with four ports. The four-way valve is an indispensable component in the refrigeration equipment. Its working principle is that when the coil of the solenoid valve is in the power-off state, the pilot slide valve is moved left by the right compression spring, and the high-pressure gas enters the capillary and enters the right-side piston cavity. On the one hand, the gas in the left piston chamber is discharged. Because there is a pressure difference between the two ends of the piston, the piston and the main slide valve are moved to the left so that the exhaust pipe and the outdoor unit are connected to each other and the other two pipes are connected to each other to form a refrigeration cycle.
A gate valve is a valve that uses a gate as an opening and closing element and moves in a vertical direction along the axis of the valve seat to achieve opening and closing movements. The gate valve can only be fully opened and fully closed, the opening and closing part is a gate, the direction of movement is perpendicular to the direction of the fluid, and the two sealing surfaces of the square I-shaped gate valve form a wedge shape, and the wedge angle varies with the valve parameters, usually 5°, medium temperature When it is not high, it is 2°52'. Improve the craft of the gate valve and make up for the deviation of the sealing surface angle during the processing. This kind of gate is called elastic gate.
A butterfly valve means that the closing member (valve or butterfly plate) is a disk, which rotates around the valve shaft to open and close a valve. The valve mainly serves to cut off and throttling. Butterfly valve opening and closing device is a disc-shaped butterfly plate, rotating around its own axis in the valve body, so as to achieve the purpose of opening and closing or adjusting. The butterfly valve is suitable for conveying various corrosive and non-corrosive fluid media in engineering systems such as furnace, gas, natural gas, liquefied petroleum gas, city gas, hot and cold air, chemical smelting and power generation environmental protection, etc., for regulation and truncation. The flow of media. Butterfly valves are classified into: handle butterfly valves, turbine butterfly valves, pneumatic butterfly valves, and electric butterfly valves.
Ball valve refers to the use of a ball with a circular through hole for the opening and closing parts, the ball with the valve stem to achieve the opening and closing action of the valve. Standard GB/T21465-2008 "The terminology of valves" is defined as: The valve (sprung) is driven by the valve stem and rotates around the square ball valve as the axis. The use can also be used for the adjustment and control of fluids, in which the hard-sealed V-shaped ball valve has a strong shear force between the V-shaped ball core and the metal seat of the hardfacing alloy, and is particularly suitable for containing fibers and tiny solid particles. Material and other media. The multi-pass ball valve not only can flexibly control the confluence, diversion, and flow direction of the medium on the pipeline, but also can close any one of the channels and connect the other two channels. This type of valve should generally be installed horizontally in the pipeline. Ball valve classification: pneumatic ball valve, electric ball valve, manual ball valve.
Check valve, also known as check valve or check valve, its role is to prevent the pipeline in the media backflow. The bottom valve of the pump is also a check valve. Forged steel check valve has two kinds of body cover connection design: The first type is the body cover bolt connection forged steel check valve, valve designed according to this connection, its valve body and valve cover bolted, winding pad Sheet seal, the advantage is easy to repair; the second body cover full welded sealed forged steel check valve, valve designed according to this connection, the valve body and the valve cover with snails, all welding seal, the advantage is no leakage .
The balancing valve is a valve that performs dynamic and static balance adjustment under hydraulic conditions and is a special function valve. In some industries, there is a large pressure difference or flow difference between the various parts of the pipeline or container due to the medium (all kinds of flowable substances), in order to reduce or balance the difference between the corresponding pipeline or container A balancing valve is installed to adjust the relative balance of the pressures on both sides, or to balance the flow by diverting the flow.
Float valve is controlled by the crank arm and float ball to automatically control the water level of the water tower or pool. Its maintenance is simple, flexible and durable, and the liquid level control is highly accurate. The water level is not disturbed by the water pressure and the water closes tightly without water leakage. Floating ball valve is divided into ordinary carbon steel series (WCB & A105), stainless steel series (304, 316), low temperature steel series (LCB, LCC), anti-sulfur series etc. based on different use requirements.
The stop valve (GlobeValve), also known as the intercept valve, is a forced-seal valve and is one of the most widely used valves. The cut-off valve relies on the pressure of the valve rod, so that the sealing surface of the valve flap and the sealing surface of the valve seat are in close contact with each other to prevent the medium from flowing. Because the medium can only flow in one direction, the direction of the installation is directional. The globe valves can be divided into DC globe valves, angle globe valves, plunger globe valves, upper thread stem globe valves, and lower thread stem globe valves. They are durable, low opening height, easy to manufacture, and easy to maintain. Not only applies to medium and low pressure, but also applies to the characteristics of high pressure.