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How Does a PVC Ball Valve Work? PVC Ball Valve Operation Explained

PVC ball valves, also called plastic ball valves

A PVC ball valve is a plastic valve that uses a ball as the shutoff component. It can also be a manual type or used with an actuator. We wrote this article to explain how this valve type works. Get to understand the different types of PVC ball valves, too, and how to tell if the valve is open or closed, among other topics.

How Does A PVC Ball Valve Work?

A PVC ball valve relies on a rotating ball to open or close. The ball has a bore in its middle. It also connects to a handle or actuating mechanism at the top. Here’s a brief look at the parts that make it.

  • Valve body: the valve housing, or what you see from outside
  • Ball: the round, hollow component that rotates to allow or shut off flow.
  • Seat: The part that seals the valve by making secure contact with the ball
  • Stem: Connects the ball to the handle
  • Handle: the handle is the part that you turn for the on/off position

To open the valve, turn the handle 90 degrees to one side. Doing so aligns the bore in the valve ports, allowing media flow.

To close the valve, turn the handle in the opposite direction. The ball closes the flow path, contacting the valve seats to provide a secure seal.

The PVC or plastic ball valve is an inexpensive and fast-acting fitting for various applications. These include plumbing systems, oil and gas installations, manufacturing plants, etc.

PVC union ball valve
PVC union ball valve

Types of PVC Ball Valves

PVC or plastic ball valves have design differences, which also mean a difference in their working principle or operation. The main types of this valve are the check, three-way, vented, and union valves: here is more about them and their working principles.

PVC Ball Check Valve

When the reverse flow of media is unwanted, the check valve is the fitting to use. The valve works by only allowing flow in one direction and preventing contamination, among other benefits.

To achieve that, it features a ball that automatically moves to shut flow in the event of backflow. It does so using either backpressure and gravity or the force of a return spring.

3-Way PVC Ball Valve

A 3-way PVC ball valve uses three ports to control the water flow or other, with the ports’ arrangement giving it an L or T shape.

Turning the handle allows users to alter the media flow through the three ports and help mix media, redirect it, or any other control action.

Vented PVC Ball Valve

The vented valve has a hole drilled in one side of the ball. In the event of pressure buildup, the hole acts as a relief, regulating the pressure and protecting the valve from damage.

Vented ball valves are helpful in cryogenic applications, such as liquid gas and refrigeration or air supply lines.

A temperature differential can cause explosive expansions in these uses, endangering the entire valve and system. The vent helps prevent that by creating pressure equilibrium.

PVC Union Ball Valve

In this type of valve, the body uses threaded nuts at one end or both. These nuts allow installers to conveniently place the fitting in plumbing systems and industrial pipelines.

With a union, you can easily remove the valve for inspection or replacement. Plastic ball valves with single unions are suitable for use at pipe ends. In contrast, those with double union nuts suit applications requiring valve insertion between lines.

PVC ball valve open position with the handle parallel to the valv
PVC ball valve open position with the handle parallel to the valve

PVC Ball Open or Closed Position

How do you know if you have a PVC ball open or closed? The ball valve is a simple type of fitting that typically uses a lever for the on/off position. Here’s how to know if the valve is open or closed:

Open Position

If the handle rests at right angles to the pipe (perpendicular), the valve is in the closed position. That means it turned 90 degrees to shut off the orifice, and no material flows through the valve.


If the handle is set at right angles to the pipe (perpendicular), the valve is in the closed position. That’s means it turned 90 degrees to shut off the orifice and no material is flowing through the valve.

Actuated PVC ball valves
Actuated PVC ball valves

Manual vs. Actuated PVC Ball Valve

A plastic ball valve may be a hand-operated or manual type. It may also be an actuated type and use a pneumatic or electric mechanism to open or close. Here’s more about these two types of fittings.

Actuated PVC Ball Valve

The actuated valve has a mechanism to operate its on/off positions. Depending on the required advantages and application needs, the actuator is usually either an air-operated or electric mechanism.

Using an actuator allows for the convenience and efficiency benefits of automation. For example, you can control the valve remotely and stop flow in an emergency. The image above shows actuated ball valves.

Manually Operated PVC Ball Valve

The manual valve uses a hand-operated handle for on/off. The handle rotates the ball to stop or allow media through the valve when turned.

Manual ball valves are a simple design, inexpensive, and easy to use to maintain. As such, you’ll mostly find them in the plumbing systems of homes and other buildings.


The PVC ball valve is one of the most used pipe fittings today. It offers a durable and lightweight material for many applications ranging from home plumbing to industrial plants. It’s also inexpensive, costing less than metal types and suiting most projects. Another significant benefit of this type of valve is the ability to withstand extremely low temperatures.

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