Valves are critical components in any system that involves fluid movement, whether liquid or gas.
These devices control fluid flow by opening and closing passages, regulating pressure and direction, and preventing backflow.
They are crucial in many industries, such as oil and gas, power generation, water treatment, and manufacturing.
Various valve types are available in the market, each designed for a specific application. This article will discuss the different valve types and their uses in flow control.
Globe Valves
Globe valves, or linear motion valves, are one of the most commonly used valve types in flow control.
They consist of a movable disk or plug positioned perpendicular to the flow direction within a stationary ring seat. This design allows for precise throttling and control of fluid flow.
One significant advantage of globe valves is their ability to regulate accurately even at high pressures.
It makes them suitable for applications requiring a high degree of control, such as steam systems.
However, globe valves have relatively high-pressure drops compared to other valve types, which can lead to energy losses and increased operating costs.
Globe valves are available in various materials, including cast iron, carbon steel, stainless steel, and brass.
They also come in different sizes, pressure ratings, and end connections to meet specific application needs.
In addition, manufacturers can equip globe valves with various actuation methods, such as manual handwheels or electric motors, for remote operation.
Ball Valves
Ball valves are quarter-turn rotational motion valves that use a spherical ball with a hole or bore in the middle to control flow.
The ball is rotated by a handle or actuator, allowing for easy and quick valve opening and closing.
Ball valves are known for their reliability and long service life. They have low operating torques, making them suitable for automation and remote operation.
Ball valves can also handle high pressures and temperatures, making them ideal for various applications, including cryogenic services.
One major disadvantage of ball valves is their limited throttling capabilities. The ball valve design allows for either full or no flow, making it unsuitable for precise control operations.
In addition, the sealing surfaces of ball valves are prone to wear and tear, which can cause leakage over time.
Cryogenic Valves
Manufacturers specially design cryogenic valves to operate in extremely low temperatures, typically below -100°C.
These valves are crucial in industries that handle cryogenic fluids, such as liquefied natural gas (LNG), liquid oxygen, and liquid nitrogen.
The materials used in cryogenic valves must withstand extreme cold temperatures without becoming brittle or cracking.
The most commonly used materials for cryogenic valves include stainless steel, aluminum, and nickel alloys.
These valves are also designed with features to prevent cold air from reaching the valve’s internal components, minimizing potential damage.
Cryogenic valves come in various types, including globe, gate, ball, and check valves. They are also available in manual or actuated designs for remote operation.
Manufacturers must rigorously test and certify cryogenic valves to ensure they withstand the extreme conditions they are designed for. Visit valveman.com for more information on cryogenic valves.
Butterfly Valves
Butterfly valves are quarter-turn rotational motion valves that use a disc with a shaft passing through it to control flow.
The disc is positioned parallel to the flow direction and rotates to control fluid flow. Butterfly valves are known for their quick and easy operation.
One significant advantage of butterfly valves is their low-pressure drops, making them suitable for large-volume applications.
They are also relatively compact and lightweight, making them cost-effective and easy to install. However, butterfly valves have limited temperature and pressure ratings compared to other valve types.
Butterfly valves come in various materials, including stainless steel, carbon steel, and cast iron.
They are also available in different designs for multiple applications, such as wafer-style and lug-style.
In addition, manufacturers can equip butterfly valves with manual handwheels or pneumatic or electric actuators for remote operation.
Diaphragm Valves
Diaphragm valves are linear motion valves that use a flexible diaphragm attached to a compressor to control flow. You can raise or lower the diaphragm, allowing fluid flow to pass through or stop.
One significant advantage of diaphragm valves is their ability to handle corrosive and abrasive fluids without leakage, making them suitable for applications in the chemical and pharmaceutical industries.
Diaphragm valves are also relatively easy to maintain and have low-pressure drops.
However, diaphragm valves have limited pressure and temperature ratings compared to other valve types. They also have a higher chance of clogging due to the flexible nature of the diaphragm.
Diaphragm valves come in various materials, including plastic and metal. They are also available in manual or actuated designs for remote operation. You can use diaphragm valves for both on-off and throttling applications.
Pinch Valves
Pinch valves are linear motion valves that use a pinching mechanism to control flow. The valve opens by compressing a rubber sleeve or tube to allow fluid flow and closes by releasing the pressure on the sleeve.
Pinch valves are known for handling corrosive and abrasive fluids without leakage. They are also relatively low-cost compared to other valve types, making them suitable for applications requiring frequent replacement.
However, pinch valves have limited temperature and pressure ratings, with the rubber sleeve being the weak point in pressure resistance. They are also not suitable for throttling operations.
Pinch valves come in various materials, including plastic and metal. They are also available in different designs, such as open and closed-body styles.
Manufacturers can equip pinch valves with manual handwheels or pneumatic actuators for remote operation.
