What Are Ball Valves Used For?
Ball valves are stop valves that use a ball to stop or start the flow of fluid.
We have talked about stop valves before, and how unlike throttle valves which regulate flow, they completely start and stop fluid flow. At least they should anyway, if you understand English and comprehend the sentence I just wrote, ball valves are not throttle valves and should not be used to regulate fluid flow.
Just like gate valves, if you use them to throttle flow, you will shorten their lifespan which ultimately means more work for you. Or me. Don’t let me catch you doing it.
Ball valves are used extensively in industrial applications because they are very versatile. They can support pressures up to 1000 bar, which is over 14,000 psi, and temperatures up to 752°F (500°C) depending on the ball valve design and construction material. Plus, they are super easy to repair and operate as you can see from the pics. What is there, like 6 pieces?
They are simple really, one of my favorite valves to use due to the both the ease of maintenance and operation.
The internal ball performs the same function as the disk in a globe valve. When you operate the handle to open the valve, the ball rotates to a point where the machined hole through the center of the ball is in line, a straight shot through, with the valve body inlet and outlet.
When the valve is closed the ball is rotated so that the hole is perpendicular to the inlet and outlet of the valve body, and flow is stopped. Usually ball valves only require like a 90 degree range to be fully open or fully closed.
Depending on the position, open or closed, the operating handle will either be inline (open) or perpendicular (closed) with the port position. This allows you to perform a quick glance and check the position of the valve. This works 99% of the time and only doesn’t work if someone really screwed up and put the handle on completely wrong. Idiots.
Ball Valve Characteristics
Aside from the reasons above – an operator can completely start/stop flow, they are easy to inspect visually, there is just a little bit more you should know about using or installing a ball valve.
Again, most ball valves are quick acting, they require only a 90 degree turn to operate the valve either completely open or closed. Some however can be gear operated. When gearing is used, the valve then requires less force to operate it. This also means we could use a smaller handwheel and save on space. One drawback though is that using gears increases the operating time for the valve.
Some ball valves even have a swing check located within the ball to give the valve check valve capabilities.
Ball valves are durable and they are reliable choices if you don’t plan on operating them frequently. Globe valves on the other hand almost like being cycled, it lubricates the packing, etc. Ball valves can just sit there and will most likely shut off most, if not all, flow even after being inactive for years. This makes them an excellent choice for shutoff applications (and are often preferred to gate valves for this purpose).
They do not provide the fine control that may be necessary in throttling applications and should not be used for this purpose.
The body of ball valves may be made of a variety of metals such as brass or even plastic. You have probably seen plastic ball valves in outdoor irrigation or sprinkler systems. The ball is often chrome plated to make it more durable which helps to prevent any fluid leaking by.
Ball valves are stop valves and should be used in applications or systems where the starting and stopping of fluid flow is desired and when very little headloss, or friction, is desired through the valve. Since it is just an inline open port, there is very little energy loss while passing through. The fluid has to work less hard to make it through when compared to a globe valve.
You should now know why and when we would want to use a ball valve and we also went over some common characteristics. They can be metal or plastic, they are simple to rebuild or repair, and they usually offer at least a little bit of a visual position indication.
If you have any questions or comments, you know the drill. If you are a master of ball valves, we’d love to hear from you.
Apollo Valves – Full Port Stainless Steel Ball Valve