The Most Common Types of Valves and Their Purpose

The valve might be a tiny device, but it has great importance in virtually every industrial process. Whether we’re talking about water and sewage processing, processing of oil, gas and petroleum, plastic manufacturing, power generation, irrigation, food production or even mining, there’s some sort of valve controlling each of these processes. And let’s not forget that these devices are also found in our homes, or more specifically in taps, dish and clothes washers. Valves are even responsible for the smooth running of the most important system of all – our cardiovascular system.

What their purpose is in these various systems is to regulate and direct the flow of the fluid while maintaining the desired pressure level. The way they do this is by closing, opening or slightly obstructing the passageways of the fluid. Because this small instrument has many uses it comes in many different designs to meet the needs of a specific application. While we could talk about the many varieties all day, there are two types of valves which are especially popular.


Ball Valves

A ball valve is a type of quarter-turn operated valve that consists out of a a perforated, hollow ball and handle. This valve is used for quick and complete flow shut-off. In normal state, the hole in the ball is aligned with the flow and hence the fluid manages to pass. But when the handle rotates the ball in 90 degrees, the valve closes and the flow stops. It’s not recommended that you use this kind of valve in an semi-open position because there will be a misalignment of the flow direction and hole causing large pressure drops.

What makes ball valves so popular is that they are easy to operate and can last for thousands of cycles before needing replacement. These valves find their purpose in large shut-off applications that use water, air, gas, oil or steam. One example of a ball valve used in the home is found at the back of the oven where it regulates the gas line. The fact that they do not require a professional to install them in home appliances is the reason you can easily find these valves online.

Check Valves

Check valves (also called, non-return valves), are used for directing the flow of a fluid in only one direction. These types of valves have two openings, one that allows the fluid to enter and one that allows it to leave. Although they come in a number of different sizes, check valves are generally simple and inexpensive. But what makes them so popular is the fact that they do not require a person to operate them, and most of the models don’t even have a handle.

Because they allow the fluid to move in only one direction, check valves are often used together with pumps. An example of a check valve used with a pump is the injector pump which supplies boilers with steam. These types of pumps also find industrial use as part of fluid systems in chemical and power plant. As far as the home is considered, you can find check valves as part of heating systems where they prevent vertical convection. When you’re shopping for these kinds of valves online, make sure to look for ones made out of metal, not plastic.