Introduction To Valves: What Are Valves & How Do They Work?

Introduction To Valves

There are many different types of valves and valve designs to accommodate all applications and circumstances. These valves can be used for a variety of purposes (on/off, control), fluid types (liquid, gas, etc.; flammable, poisonous, corrosive, etc.), material types, and pressure and temperature conditions.

Valves manipulate or help in fluid control and regulate the fluid flow rate in industrial applications effectively. An overview of how they operate, the several types of valves in plumbing, and some specific uses are provided in this article.

What Is a valve?

A valve is a mechanical device that regulates the flow and pressure of fluids or gases inside a system or process. In other words, a valve is a device that controls, directs, or regulates the flow of a fluid or gas by opening, shutting, or partly blocking fluid flow.

A valve’s opening can be adjusted and controlled manually or using an actuator. The actuator can be powered by hydraulics, electricity, or pneumatics. The valves must be carefully chosen since they account for a sizable portion of the industry’s overall spending on chemical processing.

Parts of Valves

Let’s go through its components;

  • The body of the valve, through which the fluid will travel.
  • The bonnet encloses the inside of the body and is attach to it.
  • Plug that exposes the liquid flowing inside the pipe and regulates, stops, or starts the flow.
  • The “Stem“-based Actuator, uses the plug to transmit mechanical power.
  • The Positioner is another component of the control valve that directs the Actuator.

Functions of valves in plumbing system

Valves are essential for boosting a process’s efficiency, enhancing quality control, and guaranteeing its dependability. The required function of the valve is the main factor to be taken into account when choosing a valve. A plumbing system includes valves for one or more of the following purposes:

  • Fluid flow can be start or stopped
  • Controlling flow rates in a pipe system
  • Pressure regulation
  • controlling the fluid temperature in a pipe system
  • Changing the direction of the flow from one path to another
  • limiting the flow to maintain system balance or avoid overpressurization
  • Avoid fluid flow in reverse
  • in the event of a system breakdown, stopping the flow
  • Improving safety in a pipe system by releasing pressure or vacuum

What are the different types of valves in piping?

Valves come in a variety of designs and are use for several different purposes.

  • Globe Valve
  • Gate Valve
  • Check Valve
  • Ball Valve
  • Butterfly Valve
  • Needle Valve
  • Plug valve
  • Pinch Valve
  • Pressure Relief Valve


Linear valves that move up and down are call globe valves. An actuator assembly linked to a disc inside the valve body regulates fluid flow. As the disc goes upward or below, a seat under pressure opens or closes. The seat opening directly correlates to the fluid flow (i.e., greater opening equals more flow; similarly, less opening equals less flow).

Globe valves are unidirectional, with a set direction of action for opening and closing fluid flow. The principal function of a globe valve is to completely shut off a fluid supply system, such as a chemical or water feed system.

There are three types of Globe valves:

  1. Y types
  2. Z types
  3. Plumbing angle valve


The most prevalent form of valves in processing facilities is gate valves. To restrict or let fluid passage, the closing gate travels in a straight line. Gate valves offer effective shutdown and are regard as ideal for practically all fluid services, including air, fuel gas, feedwater, steam, slurries, and viscous liquids.

The cost and ease of maintenance disassembly make gate valves popular. Due to their straight paths, which allow fluid to pass through them without changing direction, they have low fluid resistance.

Gate valves are generally kept in either a completely open or fully close state when in operation since they are not suitable for throttling applications. Controlling the flow is challenging due to the valve design.

There are different types of gate valves:

  1. OS & Y Gate valves
  2. Flexible Wedge Gate
  3. Split wedge or Parallel disks Gate valve
  4. Solid Wedge Gate


Ball valves got their name from the fact that they employ a ball to regulate fluid flow. It is connect to the handle by a bore in the ball.

The ball and the handle both rotate in tandem to change the bore angle. Fluid enters the ball’s bore opening and flows through the ball without encountering any resistance. Similarly to that, no fluid will flow if it is not direct toward the bore opening. The amount of bore opening a fluid encounters while flowing determines the pace of that fluid’s flow.

Ball valves can be operat swiftly, even in high fluid flow pressure situations. Their primary function is as a shut-off valve.

The different type of Ball valves:

  1. Standard
  2. Flanged
  3. Vented
  4. Brass ball
  5. Hydraulic
  6. PVC ball and
  7. Stainless steel ball Valve


Plug valves are valves that include cylindrical or conically-taper “plugs” inside the valve body that may be spun to regulate flow through the valve. To allow fluid to travel through the plug while the valve is open, plug valves contain one or more hollow sideways tunnels running through the plug. Plug valves are easy to use and usually affordable.

Types of Plug valves.

  1. Lubricated Plug
  2. Eccentric Plug
  3. Non-Lubricated Plug
  4. Expanding Plug


A butterfly valve is also known as a split, dual, folding, or double disc check valve. Butterfly valve have a disc that is fasten to a shaft by bearings, which allows for easy rotation. During the fluid’s forward flow, the disc’s halves split open toward the midline. The halves split open and shut the pipe when the flow is in reverse. The smashing force on the discs is lessen by the small distance the halves must travel. For use in HVAC (heating, ventilation, and air conditioning) systems, butterfly check valve function extremely quietly.

Different types of Butterfly valve:

  1. Wafer Type Butterfly
  2. Lug Type Butterfly
  3. Eccentric Butterfly
  4. Double Flange Butterfly
  5. Concentric Butterfly


Precision flow control is made possible by needle valves. Its name is deriv from the sharply point disc and matching seat. For activities such as chemical feed management or continuous blow-off, they are widely use. Due to the stem threads’ very tiny size, adjusting the aperture through the seat requires a significant amount of hand-wheel movement. The seat diameter of these valve is often less than the pipe diameter.


Valves are a method for fluid control and regulates gases or liquids. Valve are economical tools that guard against waste and protect equipment. It varies depending on the flow rate, medium gravity and temperature, line size, flow velocity, and pressure.

Selecting a valve is a challenging undertaking due to the abundance of accessible alternatives. In order to select the best valve for a given application, one must take into account the function that must be perform, the fluid service conditions and characteristics, the frequency of operation, the isolation or regulation requirements, the maintenance requirements, and the desired level of security and reliability. The optimal valve for your application may be recommend by valve manufacturers.

If you’re looking for a high-quality industrial valve, Emechmart is the place to go. We provide a range of globe, ball and gate valves made from various materials and with varying dimensions to fulfil the needs of diverse industries and requirements.