Today, there are several different types of valves that have been developed to target a specific use. Some valves are meant to operate in certain environments, while others are made to allow the flow of certain substances only. Other valves can be used in various applications or environments depending on their make and configuration. As such, it is important to learn about the different types of commonly used valves and what they are used for.
1. Gate valves
Gate valves are the most commonly used valves in industrial piping. They also sometimes are used in residential piping. Gate valves have a significant advantage simply because they cause less obstruction to substance flow and also lead to a very low pressure drop within the valve. They have a sliding metal gate that slides up or down to open or close the pipe’s passage, allowing flow or stopping it completely.
Gate valves are commonly used in sewage pipes and water distribution pipe systems.
2. Ball valves
Ball valves are quarter-turn operation valves. They are designed with a spherical ball (hence their name) with a hole through it. When the valve is open, the hole aligns with the pipe’s flow, allowing substance passage. When it is closed (by rotating the spherical plug by 90 degrees), the hole becomes perpendicular to the flow and stops it.
Ball valves are mostly used in shutoff applications -- mainly in systems handling steam, water, air, oil and corrosive fluids. They also can handle dusty, dry fluids and slurries but should not be used with fibrous and abrasive materials to avoid damage.
3. Butterfly valves
Butterfly valves are quite simple but very versatile. Just like the ball valve, butterfly valves are quarter-turn operated valves that are mostly used in many industries and for a wide range of applications. Its quarter-turn element ensures quick operation of the valve.
In an open condition, the butterfly disc allows flow around it aerodynamically. The butterfly valves are great for regulating flow and can handle slurries or fluids with suspended solids because they have no cavities within their bodies where solid particles can settle.
Butterfly valves are commonly used in water and air applications, as well as in pipes with large diameters.
4. Globe valves
Globe valves are commonly used in pipelines to control the flow of more viscous fluids such as oil. They are suitable for both on/off operations as well as flow rate control. In this type of valve, flow rate control is determined using the difference in distance between the lift plug and the valve seat. It is important to note that because of their S-shaped passageway, globe valves lead to a higher pressure drop than many other types of valves.
5. Needle valves
Needle valves are valves used to make relatively fine adjustments in the regulation or control of amount of flow. They have a tapered, long, needle-like valve stem that acts as the control mechanism for the valves. They are commonly used in industrial sectors with varying applications such as in pressure pump governors, automatic combustion systems, and instrumentation control.
6. Check valves
Check valves are valves designed to prevent the backflow in piping systems. They are activated by the pressure of the substance flowing in them. That is, when the fluid is flowing in a certain direction, its pressure forces the valve to open and allow flow through. But when the flow is reversed, the valve closes automatically. Closure is achieved either by back pressure, a spring, a check mechanism, or a combination of all these.
These six main types of valves are just a few of the many kinds available today. If you are considering the use of valves in your residential or industrial project, it is paramount to consult a professional for expert advice on the best option for your specific application.