A valve is a mechanical device that is playing a role in piping to control the flow of fluids either manually or self-operated. The word “valve” took from the Latin word “Valva” where the meaning of valva is “A moving part of the door”
Valves in Piping
The importance of valves in the industry always remains with their various sizes and functions. Whether the flowing material is in the liquid state or in the gas state, it is fully balanced and operated through the valve. Valves always play an important role in the industry even the fluid running in liquid, gas, or powder state, valves are installed for various purposes in piping like isolation, regulation, non-return of fluid, and many times for special purposes also. We can classify valves into two types, Self- operated valves which are check valves, and other valves are Operated valves. The selection of valves depends upon the nature of the fluid, and what to handle with it like liquid, gas, or powder.
Application of valves
Valves are used in almost every field, whether it is a simple home water tap or a process in an industrial field. Valves are widely used in almost every industrial process such as water and sewage processing, mining, processing of oil, gas, and petroleum, power generation, food manufacturing, chemical and plastic manufacturing, and many other fields.
Classification of valves
based on their function
1. Gate valve.
2. Ball valve
3. Plug valve.
4. Piston valve.
5. Diaphragm Valve.
6. Butterfly valve.
7. Pinch valve.
1. Globe valve.
2. Needle valve.
3. Butterfly valve.
4. Diaphragm valve.
5. Piston valve.
6. Pinch valve.
1. Multi-Port valve.
2. Flush Bottom valve.
3. Float valve.
4. Foot valve.
5. Line blind valve.
6. Knife Gate valve.
based on the end connection
- Screwed ends
- Socket ends
- Flanged ends
- Butt weld ends
- Wafer types end
- Buttress ends
Types of valves in piping
A wild range of valves is using in today as required by industry and can be classified on various labels. Valves are classified as isolation valves, regulation valves, non-return valves, and special valves as per their function.
Many types of valves are used as isolation valves like Gate valve, Ball valve, Plug valve, Piston valve, Diaphragm valve, Butterfly valve, and Pinch valve.
Regulation valves are the Globe valve, Needle valve, Butterfly valve, Diaphragm valve, Piston valve, and Pinch valve.
Non-return valves are check valves in which two types of valves are used, such as the Swing check valve and lift check valve.
: Valves that perform functions other than two-way isolation, such as multi-port, flushing, pressure relief, breather, and many other functions, are called special valves. And they are used in special circumstances.
Symbol of valves in piping
Valve classification based on connection
Valves are classified based on end connections like:
Screw end, Socket end, Flanged end, Buttweld end, Wafer type end, Buttress end.
Different Types of Valves used in Piping
Ball valves are rotational speed valves and are used for closed and throttling service. The flow control element consists of a sphere that rotates in a circular posture. Ball valves are available in full port design and regular port design according to the type of seat, soft seat, and metal seat.
Globe valves are widely used in both flow control and throttling service in INDUSTRIES. They usually have circular bodies from which they are named. They are linear motion valves attached to a thin plug or disc, closed on the seating surface that acts as a flow control element,
The gate valve is a commonly used valve in the industry for on/of service, also known as knife valve or slide valve. It can be used for throttling services also. gate valve is a linear motion valve having a flat disk or wedge slide in the stream of flow to act as a flow speed element. It is considered a normal valve applied in various fields like heavy oils, light oils, varnishes, viscous liquids, and many more.
This type of valve is used to make relatively fine adjustments to the flow of fluid. Needle valves can also be used for on / off and throttling services. This is accompanied by a thin ‘needle-like’ cone-shaped plug. Linear motion is a valve that acts as a flow control element. The fluid enters from the seat below which forms part of the flow path.
The needle plug allows the flow in this channel to open which is gradually increased or decreased. Needle valves are used for steam, air, gas, water, or other non-viscous liquids.
These types of valves can be used for on / off and throttling services. Pinch valves are linear motion valves that use a flexible tube or sleeve to close the valve. Pinch valves are ideally suited to deal with slurries, fluid-suspended solids, and large amounts of corrosive chemicals.
The diaphragm valve is a pinch valve known as one of the oldest types of valves, basically used for viscous and corrosive liquids. it used linear stem movement for on / off and throttling. The diaphragm valve is excellent for controlling fluid flow containing suspended solids. A stud carries a flexible and flexible diaphragm for flow and thus acts as a flow control element.
The plug valves depicted in the figure below are also called plug cock or stop cock valves and they also date back to ancient times, when used in plumbing systems by the Romans. Today they remain one of the most widely used valves for both on / off and throttling services. The plug valve is a rotary moving valve that uses a cylindrical or tapered plug as a flow control element.
The opening through the plug can be rectangular or round. Flow is regulated from closed to open during the 90 ° turn. If the opening is of the same size or larger than the inside diameter of the pipe, it is referred to as a standard port otherwise as a full port. Full port plug valves provide little resistance to flow when fully open, resulting in small pressure losses. One disadvantage of plug valves is their poor throttling characteristics.
A butterfly valve, depicted in the figure below, is a rotary movement valve that is used on flow control and especially in throttling applications. The flow control element in butterfly valves is a circular disk with its axis at right angles to the direction of flow.
Check valves are known as non-returning valves having two types Swing check valve and lift check valve. check valves are one of the oldest types. The main function of this valve to allow the fluids from one side and check from the other side.
ROLL OF VALVES
valves are used from our home appliances to industries, for all types of activities. In this way, we can say that the valves in piping are quite essential and enough to control the flow of fluids.