What are The Three Types of Valves Used in a Piping System?

For every type of piping system, the medium being handled must always remain uncontaminated.

So when designing your piping system, it’s crucial to choose the right type of hoses, pipes, fittings, and valves. Proper selection of such materials ensures the medium flowing in the system meets the required safety standards and industry recommendations.

When setting up the pipework, your system requirements will dictate the type of valves to use. Typically, there are more than seven types of valves, each designed for its unique application.

However, there are three main types used in nearly all systems. We have discussed all you need to know about these valve types in the section below.

Common Valves Used in Piping Systems

Every system has unique requirements and characteristics, so you’ll probably use different valves. For instance, if you are to regulate the flow of drinking water, you’ll need to use valves, pipes, and hoses rated for drinking water applications.

The same applies to the petrochemical, power generation, or oil & gas industries. Here are the three categories of valves you’ll find in most piping systems.

Shut-off Valves

From its name, shut-off or stop valves are valves that safely stop the flow of a fluid medium in the system. Shut-off valves are a crucial part of your plumbing system.

They are used where your piping system starts in areas near sinks, bathtubs, dishwashers, washing machines, and other fixtures. Shut-off valves come in varying designs and types, but the most popular options are gate valves and ball valves.

Ball valves are one of the most common types of shut-off valves. A ball valve controls the flow of fluid mediums by use of a rotary ball with a bore. When the ball is rotated at a 90-degree angle (from a closed position), the medium flows, and when rotated back, it blocks the flow.

The valves offer reliable sealing features and are resistant to contaminations; hence are common with most applications, including in drinking water systems.

Gate valves, on the other hand, are common due to their affordability and versatility. A gate valve has a circular handle that controls screw movement, which either closes or opens the gate to allow or restrict fluid flow.

Other types of shut-off valves include globe valves and angle seat valves.

Check Valves

Check valves are one-way valves installed in piping systems to prevent backflow. They are common in domestic and industrial systems. If the fluid medium reverses direction, the valve closes, preventing flow and protecting components such as pumps, pipes, and other valves in the piping system.

Check valves are either normally closed or normally open, and their working principle varies based on their construction.

The most common check valve type is the spring-loaded in-line design that uses a pressure differential to open or close the valve. Other types are spring-loaded Y-check valve, ball check valve, diaphragm check valve, and lift check valve.

Unlike most other valves, there are several factors to consider when choosing a check valve. These include the line size for connection points, maximum and cracking pressure requirements, installation orientation, accessibility needs, and envelope dimensions.

Solenoid Valves

Solenoid valves are often the ideal option in applications requiring irregular water supply, such as washing machines, dishwashers, or even car wash systems.

A solenoid valve is electrically actuated and is popular for its accuracy and versatility. It has an inductive coil, a metallic plunger, a spring, a diaphragm, and a small orifice that allows or restricts fluid flow.

When the valve is powered, an electric current flows through the inductive coil. This causes an electromagnetic field that exerts a force on the plunger, pulling it and opening the orifice for fluid to flow.

Once power is switched off, the inductive coil loses its magnetism, and the spring action pulls back the plunger, closing the orifice and restricting fluid flow.

These valves are fast-acting but can only be used for clean liquids and gases. They are classified based on their circuit function (2-way or 3-way), valve design (normally closed or normally open), and valve working principle (direct-acting, indirect acting, or semi-direct acting.)

Choosing a Valve for Your Applications

When choosing a valve for your piping system, the first thing is understanding the system requirements. That means knowing the industry specifications, approvals, temperature and pressure requirements, etc.

You should also understand the different types of valves you want. For instance, knowing the working principle, advantages, and disadvantages of various shut-off valves will help you choose one that works well for your system.

The valve housing material and seal material are also crucial during the selection process. Ideally, you want to pick a valve material compatible with the fluid you want to control.

If working with high-temperature and pressure fluids, choose heavy-duty materials. Other factors to consider are valve response times, IP protection, and voltage requirements (solenoid valves). If it’s your first time interacting with valves, consult a qualified professional for help.