A solenoid valve is an on/off electromechanically operated valve which involves an electromagnetic actuator (solenoid) and a valve body. The solenoid-plunger assembly is the valve actuator in charge of opening and closing the valve. This actuator can be arranged in such a way that the plunger action can either open or close only. There is no intermediate or in-between position, so there is absolutely no way for a solenoid to throttle flow. The valve body consists of the pressure containing parts in-contact with the process fluid.
The solenoid converts electrical energy into a mechanical pull/push action. This involves a coil of wire tightly wrapped around an iron core, and a ferromagnetic plug or plunger. Components vary with respect to the design. As a power current passes through the coil, a magnetic field is generated. The magnetic field lines can be imagined as some circles with the direction of its current axis. Regarding a flowing current along a looped coil, the circles incorporate forming the magnetic field.
Adding more loops will boost the amount of magnetic field lines or flux. This increases the electromagnetic force of the solenoid, which does mean more force for actuating the valve. Another way to raise the force of attraction is to improve the amount of current flowing through the coil. That is done by increasing the supply voltage in to the solenoid. Solenoids valves can operate with either DC or AC. Common DC voltages are 6, 12, 24 and 240 volts; while AC at 60Hz are 24, 120, 240 and 480 volts.
Proportional solenoid valves
Proportional solenoid valves are a particular sort of solenoid valve that provides a smooth and continuous variation in flow or pressure in response to the electrical input. This kind can be classified as a control valve. To get a solenoid valve to become a proportional valve, the plunger position must be controlled. It is achieved by balancing the plunger through an external force usually done by a spring. The planting season will compress before the external force is equal to the electromagnetic force of the solenoid. In case the position of the plunger must be controlled, the existing must be changed causing an imbalanced force on the spring. The spring will compress or stretch until force balance is set up.
One problem with this type is the effects of friction. Friction disrupts the smooth balancing of the electromagnetic and spring forces. To negate this effect, special electronic control can be used. Common method used to solenoid valves proportional control characteristics is pulse width modulation or PWM. Applying PWM signal as the control input causes the solenoid to energize and de-energize successively at a very fast rate. This puts the plunger in oscillation which nets into a stable position. In order to change the position of the plunger. The on and off states of the solenoid, also termed duty cycle, are controlled. To get more information about Solenoid Valve Manufacturers
Unlike ordinary on/off solenoid valves, proportional solenoid valves are used in applications where automated flow control is required such as proportional pneumatic actuators, throttle valves, burner controls, and so forth.
A solenoid valve is an electromechanically operated valve which involves an electromagnetic actuator (solenoid) and a valve body. Ordinary solenoid valves are two-position valves. There is absolutely no intermediate, or in-between position, so there may be no way for the solenoid to throttle flow.
Proportional solenoid valves are a special sort of solenoid valve that can throttle flow or pressure in respond to the electrical input. For a solenoid valve to become a proportional valve, the plunger position is controlled by balancing it using an external force usually done by a spring.
A solenoid valve has two main parts: the solenoid which is responsible for the opening and closing of the valve; and the valve body which provides the fluid and its own pressure.
Solenoid valves can be categorized according to its procedure and flow paths or circuit function. Solenoid valve procedure can be direct-acting, internally piloted, externally piloted or semi-direct.
Circuit functions of solenoid valves are two-way that your normal open is and close valves; three-way which features an exhaust port for relieving pressure; and four-way which is employed in flow diversion.
The valve body can be constructed by a number of materials. Factors such as the fluid properties, environment characteristics and cost affect the material specifications of the valve.
Specifying the required approvals and certifications is one of the ways to ensure getting a satisfactory solenoid valve. Compliance to standards set by international organizations guarantees product safety and quality.