Whether you’re implementing a simple piping system to transport materials or designing a complex multi-step system with automated controls, monitoring, and more, flow control is likely to be a key component of your project. We are the leading ball valve manufacturer in India.
Flow control is often implemented using stainless steel valves. However, choosing the correct valve configuration is essential to ensure safe, long-lasting performance and avoid common pitfalls.
Throughout this guide, we’ll examine two common valve designs used for flow control — ball valves and needle valves — and discuss the factors that make either the ideal choice for your process.
WHAT IS FLOW CONTROL?
In most piping systems, flow control is essential. Before discussing how valves play a role in flow control, it’s important to understand how flow control works and any considerations you may make when implementing flow control solutions.
By understanding this fundamental topic, you will be able to select the perfect valve design for your needs.
Flow control is the process of limiting or regulating the flow of liquids, gases, or any other substance through your piping system.
To help control pressure and ensure smooth operation, flow control may be used in main piping lines. In addition to monitoring and instrumentation systems, flow control is an essential component. In addition to reducing the risk of damaging sensitive instruments, it provides greater control over monitoring.
While pipe size, routing, and pressure can affect the flow of substances through a system, this is often a static situation. In most cases, you wouldn’t frequently change any of these factors since it would be time- and cost-consuming.
Depending on the state of the valve and the desired factors, valves provide a flexible means of providing variable or dynamic flow control.
TYPES OF FLOW CONTROL
There are two methods of controlling flow: on-off control and throttling control.
On-off controls function as they sound. In most cases, the valve is either fully opened or fully closed, creating a state of on or off. Although some valves work between on and off, there is no accurate way to set the exact flow rate.
The operation of an on-off valve in an intermediate state may also damage the valve or reduce its service life. Variable flow rates can be adjusted with precision using throttling control valves. The valve type and system parameters will determine the accuracy and degree of control provided.
COMPARING BALL VALVES AND NEEDLE VALVES
Ball valves and needle valves are compared based on how they relate to on-off valves and throttling valves. There’s a good chance that ball valves will be an ideal fit if all you need is on/off functionality.
Compared to needle valves, ball valves cannot begin to match their regulating capabilities. Needle valves are the best choice when fine control is essential. To determine which type of valve is best suited to your needs, let’s explore each valve type in more detail.
BALL VALVES EXPLORED
It is the design of ball valves that gives them their name. The valve has a ball at its center with a channel running through it. Rotating the ball 90 degrees exposes this channel to the flow path, allowing it to be fully opened or closed.
In applications requiring quick state switching or fully open and closed states, a ball valve is a great choice due to its short-throw actuation.
Additionally, the design allows for an exceptional airtight seal. Due to the valve seat wiping itself with each actuation and the limited number of parts, cleaning and maintenance are minimal.
A full port design is ideal for high-flow operations since pressure drops are minimal. Due to these factors, it is a versatile and cost-effective option for flow control in a variety of piping processes.
The rapid actuation and minimal travel distance that make the valve ideal for some applications make it unsuitable for situations requiring precision flow control or extended throttling.
Lastly, when using suspended solids or sticky textures, valve surfaces must be monitored for build-up and abrasion. Surfaces should be kept clean to prevent leaks and eventual valve failure.
Ball valves are commonly used in the following industries:
- Agriculture
- Construction
- HVAC
- Manufacturing
- Mining
- Oil and Gas
Brewing, petroleum refining, and marine or seawater operations can benefit from stainless steel ball valves due to their corrosion resistance.
NEEDLE VALVES EXPLORED
A needle valve blocks the flow path through the valve with a needle-shaped plunger. Plunger positioning is finely controlled by a threaded, rotating stem adjustment mechanism.
Precision allows minute adjustments to flow rates, which is an advantage. Consequently, needle valves are popular for use in valve manifolds, which facilitate the mixing of multiple processing lines.
Additionally, needle valves are highly resistant to both hot and cold temperatures and provide an exceptional service life in high-pressure or high-vibration environments.
Also, read ” What is a Motorized Valve, How Does It Work, and What Are Its Advantages”
Furthermore, they create a high-pressure drop when they are open, making metering and controlling processes even easier. These perks, however, come with tradeoffs — many of which are related to the screw-tap adjustment.
A needle valve is not suitable for situations that require rapid changes in the valve’s state. The screw handle must be rotated numerous times to move the needle-shaped plunger through its full range of motion.
Because the handle rotates so freely, it can be difficult to tell if the valve is open or closed simply by looking at it. A highly restricted flow is also created by the pressure drop and precision control. Consequently, needle valves are not suitable for processes or scenarios with high flow rates.
The following industries may use needle valves:
- Chemical processing
- HVAC
- Manufacturing
- Petrochemicals
- Pharmaceuticals
- Wastewater treatment
Needle valves are commonly used in automatic combustion control systems, fluid power systems, gas bleeder lines, metering systems, sampling lines, and vacuum systems.
Cair Euromatic Automation is the leading ball valve manufacturer in India. We offer various types of industrial valves like ball valves, butterfly valves, control valves, plug valves, and many more.
