F low control valves control the movement or pressure of fluid. A valve is basically a mechanical device that blocks a tube or pipe either partially or completely to change the amount of fluid that passes through it.
Flow control valves normally respond to signals generated by independent devices such as flow meters or temperature gauges. Valves regulate gases as well as liquids.
There are countless types of valves for use across a variety of industries and applications. When it comes to flow control valves, valve types range from simple to sophisticated; some valves are complex enough to adjust automatically to pressure and temperature variations. No matter their construction, flow control valves are designed to regulate the flow or pressure of fluids, and they typically react to signals generated by flow meters or temperature gauges.
While there are several types of flow control valves, here are six common types and how they operate.
Gate Valve
Gate valves are shutoff valves that are best used in a fully open or fully closed position. The main parts of the gate valve consists of the valve body, seat, disc, stem, gland, and handle. The seat and stem are the major components that perform the shutting off of the media. Gate valves are not great fluid regulators as these kinds of valves are prone to valve disc vibration. These vibrations cause damage to the disc.
There is going to be an increase in demand for gate valves in the coming years because of the global need for these kinds of industrial valves. Valve buyers should grab this opportunity and look for great gate valve prices in South Africa.
READ: Thermoplastic valves manufacturer, Asahi, acquires its S. Africa distributor
Knife gate valves, in particular, will take the limelight due to their various applications particularly in pulp & paper, wastewater treatment, sugar-making, and chemical processing industries.
Butterfly Valves
Butterfly valves can be used as a shut/off or throttling valve. It is compact, lightweight and takes little space. This kind of valve is suitable when the application requires a shutoff valve with a bubble-tight seal but placed in a tight space.
Butterfly valves can be classified according to the orientation of the butterfly valve seat. These can be concentric, double eccentric and triple eccentric. Butterfly valves are often used in pharmaceutical, chemical, and food industries.
Non-Return Valve
Non-return valves only allow the media to flow in one direction. This kind of valve is installed in the pipe where conditions may cause reversed flow due to changes in pressure.
There are many different kinds of non-return valves. Some of these are spring-loaded type, swing type, and the clapper type. Non-return valves are often associated with back flow prevention in water systems.
Ball Valve
Ball valves are one of the commonly used valves in industrial applications. These are quarter-turn valves that are often used to isolate or shutoff media. Ball valves can either be trunnion-mounted or floating, based on the ball disc design. Ball valves can be also be classified depending on body style. These can be made of a single body, split body or top entry.
Pressure Relief Valve
Pressure relief valves are sometimes known as safety relief valves. These valves are designed to open at a preset pressure level and relieve the valve of excess pressure. This valve also allows for the pressure level to return to normal. There are two kinds of pressure relief valves. These are direct-acting dead-weight pressure relief valves and direct-acting spring valves.
Solenoid Valve
Solenoid valves are valves that use electromagnetic actuators for opening and closing. These valves are used to control the flow of media in pneumatic and hydraulic fluid systems. The most common solenoid valves have “normally open” or “normally closed” versions.
The normally open type is open at all times except when it needs to be closed. The normally closed type is blocked at all times except when it needs to be opened.