Do you deal with gases and liquids? Controlling the flow rate or pressure of such mediums through a pipeline is something you will always have to do. But it isn’t a hard thing to achieve today since flow control valves have made everything easy.
You need a flow control valve to optimize system performance that relies on a flow passage. Besides, when using a hydraulic flow control valve, it can help to check the rate of energy transfer at a specific pressure.
How flow control valves work
Many flow control valves are in the market and are designed for specific applications. So, if you seek to buy a control valve, ensure you understand how each functions. That way, you can select the right valve that meets your needs. But the simplest flow control valve has an aperture that opens or closes to increase or slow down the flow rate.
For the automatic flow control valves, opening and closing of the valve is done by pneumatic actuators, hydraulic or electrically. To achieve the desired degree of opening, some flow control valves use valve positioners. A valve positioner helps to overcome the issues related to friction and wear.
You can use a flow control valve in heat and water supply systems. They are also the best to use when dealing with oil and gas pipelines. Even in chemical industries, the flow control valves play a crucial role in controlling liquid flow rates.
Factors to consider when buying a flow control valve
- Connectivity of the process
- Level of noise tolerance
- Acceptable leakage limit
- The required pressure drop across the flow control valve
- The corrosive aspect of the liquid to be controlled
- Minimum and maximum fluid flow rate
- Fluid density.
Major types of flow control valves
1. Ball valves
This is among the simplest types of flow control valves. A ball valve has a ball connected to a handle. A hole is found through the center of the ball. Once you turn the hand of the ball valve, the hole becomes aligned with the valve openings, which permits the flow. When you want to shut off the flow, you use the handle to turn the whole perpendicular to the ball valve openings, and that will obstruct the flow.
2. Needle valves
You got a more precise valve option with this type. A needle valve has an adjustable needle and valve stem that helps to restrict or allow the fluid to flow. When you want to completely block the fluid flow, you just need to adjust the needle, and it will be done! The valve also allows you to let the free flow of your liquid or partially control the flow to a varying degree.
3. Butterfly flow control valve
This is a quarter-turn rotational motion valve. You can use the butterfly valve to start the flow, regulate, or even stop the flow completely. The valve is fitted with an internal metal plate connected to a turning mechanism. After the mechanism is turned, the plates open or closes. A 90º rotation of the valve’s handle gives a complete opening or closing of the valve. You may go for a butterfly flow control valve if you are looking for an easy and faster to open the valve.
Butterfly valves are designed to handle large flows of gases or liquids, mainly at relatively low pressure. You can also use them in controlling slurries and liquids with large suspended materials. The valve has minimal mobile parts, which keep the cost of maintenance low.
4. Diaphragm valve
A diaphragm valve is bi-directional. It’s an on-off throttle valve you can use to control liquid flow by regulating the area where the fluid enters and exits the valve. This type of valve has a thin and flexible membrane that controls the closing and opening of the valve to effectively change the speed and velocity of fluid flow.
While diaphragm valves appear like pinch valves, they apply a linear compressor to push the thin diaphragm to the valve body. You got the best flow control valve with this one if you are looking for a clean and leak-proof valve. Besides, a diaphragm valve is safe and easy to maintain. If the fluid you seek to monitor is characterized by moderate temperatures and pressure, a diaphragm valve will be the most effective to use.
Challenges associated with flow control valves
The flow control valves offer a cost-effective solution to flow rate concerns. But they also have their challenges. Any loss of pressure resulting from partial obstruction affects the performance of the flow control valve. Even when the valve is in a static position, you may experience changes in flow rate due to temperatures and system pressure. That will require you to use more sophisticated flow control valves to avoid such issues.
A flow control valve offers a great solution when seeking to monitor flow rate with precision. As the valve opens and closes, it helps to control the rate of fluid flow in a pipeline. You will find various types of control valves in the shops. That’s why you need to understand how each functions before buying.