Pressure balancing in valves. Other types of valves. The design and function of control valves. Valve sizes DN. Nominal pressure and pressure. Different types of valves are used in piping. In this article, I have covered classifications of valves and functions of valves. Let's start with Valve definition. Valves are quite diverse and may be classified into a number types. Basic Types - by operating . Create a book · Download as PDF · Printable version.
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There are a large variety of valves and valve configurations to suit all services and The following types of valves are used in a variety of applications, these. VALVES. Program Objectives. By the end of this module, trainees will be able to: • Define a valve. • Identify the different types of common valves used at Sunrise. Many different types of manual valves are used in industrial applications worldwide. The following article will cover the general mechanism and function of the.
Thermal expansion valve , used in refrigeration and air conditioning systems. Safety valve or relief valve : operates automatically at a set pressure to correct a potentially dangerous situation, typically over-pressure Specific types[ edit ] These are more specific types of valves, used only in particular fields or applications. Often they are subcategories of the classification by operating principle and by function. Aspin valve : a cone-shaped metal part fitted to the cylinder head of an engine Ball cock : often used as a water level controller cistern Bibcock : provides a connection to a flexible hosepipe Blast valve : prevents rapid overpressuring in a fallout shelter or a bunker Boston valve: three-part two-port check valve used on inflatable boats, air mattresses, airbeds etc.
Ceramic disc can also provide Class IV seat leakage Choke valve , Butterfly valve used to limit air intake in internal combustion engine. Not to be confused with choke valves used in industrial flow control. Materials used for the valving element and sealing can limit their applications at higher temperatures or with certain types of fluids. Butterfly valves are often used on applications for water and air, and in applications with large pipe diameters. In this type of valve, flow rate control is determined not by the size of the opening in the valve seat, but rather by the lift of the valve plug the distance the valve plug is from the valve seat.
Different Types of Valves used in Piping – A Complete Guide of Pipe Valves
One feature of globe valves is that even if used in the partially open position, there is less risk of damage to the valve seat or valve plug by the fluid than with other types of manual valves. Among the various configurations available, needle type globe valves are particularly well suited for flow rate control. Another point to consider about globe valves is that the pressure drop across the valve is greater than that of many other types of valves because the passageway is S-shaped.
Valve operation time is also longer because the valve stem must be turned several times in order to open and close the valve, and this may eventually cause leakage of the gland seal packing. Furthermore, care must be taken not to turn the valve shaft too far because there is a possibility it could damage the seating surface. The construction of a gate valve is similar to that of a floodgate: The latter two types help prevent the valving element and body from being deformed due to various operating conditions.
Like ball valves, gate valves are not usually used to regulate flow. One of the reasons for this is because the valving element can be damaged when in the partially open position. Similarly, they also limit the pressure drop across the valve when fully open.
However, setting the valve to the fully open or closed position requires the handle to be turned many times, which generally makes these valves have the longest operating times among those valve types mentioned here. Diaphragm valves use a 'pinching' method to stop the valve flow using a flexible diaphragm.
They are available in two types: The most commonly seen of the two is the weir-type. This is because the straight-way type requires additional stretching of the diaphragm, which can shorten the diaphragm's life-span. One of the major advantages of using diaphragm valves is that the valve components can be isolated from the process fluid.
Similarly, this construction helps prevent leakage of the fluid without the use of a gland seal packing as seen in other types of valves.
One the other hand, the diaphragm becomes worn more easily and regular maintenance is necessary if the valve is used on a regular basis. These types of valves are generally not suited for very high temperature fluids and are mainly used on liquid systems.
There exists a valve for steam systems that goes by a similar name.
It is an automated valve with a diaphragm type actuator. This is often shortened to just 'diaphragm valve', so when a valve is referred to by this name, care must be taken to verify which type of valve it is.
Such as multiport, knife, and line blind valve. Another way to classify the valve is the way it open and close. Each valve opens and closed by either Liner or rotary motion or by quarter turn which is nothing but a rotary motion.
In the image below, you can see the difference between opening methods of the valve. Linear motion valves use a closure member that moves in a straight line and cut the flow to start, stop, or throttle the flow.
The closure device could be a disc, or flexible material, such as a diaphragm. Linear motion valves are slower in operation, but they provide a higher level of accuracy and stability in the position of the closure member. Rotary motion valves rotate a disc or swing it from the hinge pin that holds the disk.
Because of this quick turn, the operation of Quarter turn valve is much faster than linear motion valves. Some rotary motion valves are also known as Quarter turn valve. In the table, you can see that ball valve, butterfly valve, and plug valve are both rotary and quarter turn valve.
Whereas swing check, tilting disk, and other rotary motion valve are not a quarter turn valve. The last way to classify the valve is, types of the actuator is used to transfer the motion to operate the valve.
Valves, Types and Operations
The valve can be operated manually with the help of handwheel, lever, chain or by a gear wheel. An external power source such as an electric motor, air, hydraulic fluid or solenoid is used to operate valve from the control room.
Check valve works automatically when subjected to the backflow. Skip to content Skip to primary sidebar. You are here: What is Valve? Valve type. Linear motion. Quarter turn. Tilting-disc check valve. Folding-disc check valve.Check Valves. Needle valves are designed to give very accurate control of flow in small diameter piping systems.
A pressure Relief valve or pressure safety valve are used to protect equipment or piping system during an overpressure event or in the event of vacuum.
Butterfly valve has a short circular body. It means that if you choose ball valve over butterfly valve for the same function. The seat matching the ball is circular so that the seating stress is circumferentially uniform.