If you’re wondering how liquid control valves work, they regulate liquid flow. And they come in various types, each performing a specific application. For example, high-pressure control valves operate when pressure reduction is necessary between the two parts of a process.
Different Types of Liquid Control Valves
While these come in a variety, below, we’ll mention some flow control valves with features that make them suitable for various applications. Ball valves have an inner ball attached to a handle-it can allow or stop the flow when turned on. Then we have Butterfly valves-these use a metal plate that opens and closes the aperture. Apart from the device attached to the handle, these are similar to the ball valves.
Last, we have needle valves-these use a needle to control the system to open and close the liquid flow.
Most Popular Liquid Flow Valves
High-pressure Control Valve
Due to its high versatility, this product works well in both liquid and gas control applications. For example, it can work on liquid dump applications and gas applications such as backpressure regulation.
This valve will stay in its fail position (open or closed) unless commanded otherwise.
When operating in a liquid dump application, it gets a pneumatic signal from a fluid level flow controller. That’s how it knows when to open and dump the liquid.
A Liquid Dump Valve
Five parts make up a mechanical liquid level control. One is a liquid dump valve, float arm, float, trunnion, and linkage rod. You’re most likely to find this liquid level control component in production vessels. It maintains and controls fluid levels.
You connect this dump valve to downstream piping. As the float rise to the set level, the linkage rod does the same and lifts the arm on the dump valve. It opens the valve, letting go (dumps) of the liquid from the vessel downstream for more processing.
Pinch Valves
These are some of the cost-effective flow control valves. They work well in applications of slurries or liquids that have significant amounts of suspended solids. Pinch valves use several flexible elements to seal elements like rubber tubes that get pinched to obstruct the flow and close the valve. Unlike the ball or gate valves which can have particles trapped around them, the rubber sleeve in a pinched valve can trap the particles and close appropriately.
In essence, a pinch valve has a built-in actuator that helps to eliminate expensive pneumatic, hydraulic or electric operators.
Gate Valves
Gate valves work in non-throttling services and applications that require a straight-line flow with minimum restriction. These valves operate as the user rotates the stem clockwise to close (CTC) motion or open (CTO) motion. Gate valves can work for several fluids, and they are generally applicable for potable water, neutral liquids, and wastewater.
Globe Valves
Globe flow controller initiates closure through a plug with a flat or convex bottom-placed onto a horizontal seat in the center of the valve. Since the disc of the globe valve can completely close the flow path, and you can also remove it, they are ideal for throttling applications. And through the linear motion valve, globe valves can start, stop and regulate the flow.
As you open the valve, the plug raises and allows fluid flow. This flow control valve produces higher pressure drops than straight-through valves, including ball and gate valves. That’s why they are appropriate for applications with pressure drop where the valve is not a controlling factor.
In Conclusion
Liquid control valves come in a wide range, including mechanical, electronic, and electro-pneumatic-operated valves. Their primary role is to regulate pressure and liquid or gas flow rate. But a primary valve has an opening that an operator uses to adjust the flow rate. Manufacturers can get several options from simple to complex systems that change temperature, pressure, and other flow variables.