Warm greetings to all 🤩in the 19th post on #Day19 ! Today, we will resume learning the 2nd part of the Valves, which is Rotary Valves. Here we go🧨,
Short introduction🧨
Rotary valves include any valve that closes by the rotational, spinning motion of a structure within the valve. These include ball, plug, and butterfly valves.
Ball🧨
Ball valves are the most common and versatile type of rotary valves. A typical ball valve is pictured below.
General Information
The rotary valves pictured below use a ball-shaped disk with a hole bored through to stop or start fluid flow. By turning the handle a quarter turn, the valve is turned to either the opened or closed position. When the valve is opened, the ball is rotated so that the hole is aligned with the valve's body's inlet and outlet. When the valve is closed, the ball is rotated so that the hole is perpendicular to the flow. Ball valves are quick opening and closing and have tight shutoff characteristics.
The ball moves across the seat with a wiping motion. As a result, ball valves can handle fluids that contain suspended solids.
Equipment Design
The picture below shows the major components of a ball valve. When you turn the handle 90°, the ball turns 90°, shutting off the flow.
Ball valves are compact, easy to maintain and provide good shutoff characteristics.
The picture below (1) shows a unique example of how easy it is to take a ball valve apart for cleaning. Some ball valves are made from PVC pipe, as shown below (2). These pipes are ideal for high corrosion applications, such as handling strong acids.
(1):
(2):
Usage Examples
Ball valves are manufactured to handle a variety of fluids including corrosive chemicals, viscous liquids, gases and even acids. Ball valves such as the one pictured below to the right can be used in cryogenic temperatures ranging from -130°F to 32°F.
📌Advantages
Highest flow capacities.
Low pressure drop and low leakage.
Rapid opening and relatively contamination-free.
Pocket ball valve can be used for quick, in-stream sampling.
📌Disadvantages
Limited to low temperatures that have little effect on their plastic seats.
Typically, the entire valve must be removed from the line for maintenance.
Some fluid may be trapped in the ball in the closed position, damaging the valve.
Due to rapid opening, surge pressures may arise which could damage equipment downstream.
Plug🧨
Plug valves are the oldest and simplest type of valve still used in industry. The picture below shows a typical plug valve.
General Information
Plug valves are quick opening and closing and they do not leak. Plug valves are very similar to ball valves. Instead of a ball, a rotary cylinder or tapered plug with a hole through it is rotated 90° to allow or prevent flow. Plug valves, like ball valves, are not used for throttling.
Plug valves often have fluorocarbon seating materials and sometimes they are fully lined with fluorocarbon. This provides excellent protection for corrosive applications that require bubble-tight shutoff.
Equipment Design
The schematic below shows the major components of a plug valve. Ball bearings beneath the cylinder reduce friction and provide easier rotation of the plug. Some plug valves have a lubricant beneath the cylinder instead of ball bearings.
Usage Examples
Plug valves are typically found in the gas industry and the wastewater industry. The picture below shows a three-way valve designed for shutoff services. Plug valves are often used in the waste water industry because they do not allow buildup of sediments, which could clog the pipes.
here are also several types of plug valves commonly used in Chemical Plant Industries (CPI); these include lubricated, non-lubricated, and eccentric types.
📌Advantages
Pressure drop is low.
High flow capacities.
Low leakage.
Rapid opening and relatively contamination-free.
📌Disadvantages
Some fluid may be trapped in the cylinder while in the closed position, damaging the valve.
Due to rapid opening, surge pressures may arise which could damage equipment downstream.
Butterfly🧨
Butterfly valves are the largest type of valve, and they are commonly used for gas and steam control. This picture shows a butterfly valve in the closed position.
General Information
Butterfly valves have a very simple design. They consist of a flow controlling disc that rotates about a shaft that opens and closes at right angles to the flow path. Turning the handle a quarter turn makes the disc rotate to the open position, which allows maximum flow. The picture below shows the direction of the flow when the valve is in the open position.
Equipment Design
The rotating disc is the same size as the internal diameter of the pipe. Seals are needed to help prevent leaking. The pictures below show a butterfly valve fully open. Notice the disc is parallel to the flow path, allowing for the least pressure drop and maximum flow rate.
Usage Examples
Butterfly valves are typically used in large pipes with diameters greater than 4 inches, and in situations in which some leaking is relatively unimportant. They are applicable for both on/off and throttling applications. The picture below shows butterfly valves that are used as shutoff valves for pump isolation.
📌Advantages
Require less space than any other valve.
Inexpensive.
Excellent flow characteristics.
Require a steady amount of force to open/close the valve.
Very low pressure drop.
📌Disadvantages
Slow response characteristics.
Require large actuator forces.
Must be custom-designed for each use.
References📖
http://encyclopedia.che.engin.umich.edu/Pages/TransportStorage/Valves/Valves.html
Gas Conditioning and Processing Volume 1, 7th edition
Additional Resources 🧪🔑
You can get deep insight about Process/Chemical Engineering from these sources😉:
https://t.me/ebookstorage/211-Elementary Principles of Chemical Processes
https://t.me/OilAndGas/18122- Valve Sizing Sheet
https://t.me/ebookgate/1127- Engineering Fluid Mechanics Book
https://coursemania.xyz/course.html?id=433291- Free course on Fundamentals of Fluid Mechanics
https://t.me/ebookstorage/178- Engineering Heat Transfer
https://t.me/ebookstorage/159- Fundamentals of Engineering Thermodynamics (9th Edition) (2018)
https://t.me/ebookstorage/183-Heat Transfer applications and principles
https://t.me/ebookstorage/171-Design and Operation of Heat Exchangers and their Networks (2020)
https://t.me/ebookstorage/215- Industrial Separation Processes (book)
https://t.me/ebookstorage/214- Advanced Process Engineering Control (book)
https://t.me/OilAndGas- Information about Oil&Gas (mainly arabic lang)
https://t.me/chemical_worlds- Chemical Engineering Books, Quizzes and GATE Study Group
https://t.me/chemical_environmental- Discussion group related to Chemical Engineering Problems
https://t.me/chemicalengineeringworld_cew- Everything related to Chemical Engineering
https://t.me/ebookgate- Chemical Engineering E-books (Telegram Channel)
https://www.youtube.com/channel/UCqioh32NOJc8P7cPo3jHrbg- Piping Analysis
https://www.youtube.com/channel/UCQfMyugsjrVUWU0v_ZxQs2Q -Mechanics of engineered devices
http://chemicalengineeringguy.com/- suggests a wide range of courses in Chemical engineering (you can find free courses on topic of Aspen HYSYS, Aspen Plus)
https://www.youtube.com/user/LearnEngineeringTeam- suggests working principles of every engineered devices, equipment and etch.
https://www.youtube.com/channel/UCR0EfsRZIwA5TVDaQbTqwEQ- suggests great information about pumps, compressors with animation.
Today we have resumed learning about Valves. Tomorrow, we will continue learning the 3rd part of Valves. Now, time to say goodbye👋🏻 until tomorrow and Stay tuned for more content 😉🌝✨! ✏️Note: If you need one of those books or links, you can contact me via my email or LinkedIn profile. #process #processengineering #engineering #chemical #chemicalengineering #technical #education #dailypost #newpost #wixsite #day19 #bernoulli #technology #material #materialbalance #mass #massbalance #project #projectengineering #selfdevelopment #challenge #recycle #streams #purge #improvement #fluidflow #flow #fluidmechanics #fluiddynamics #water #waterhammer #contuinity #energy #equations #Pfd #processdiagrams #diagrams #piping #instrumentation #pid #development #examples #study #studentlife #fluidstatics #valves #gatevalves #globevalves
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