What is a ball check valve ?
A ball check valve is a check valve, a ball check valve is labeled by the mechanism that makes the valve work. The movable part that is responsible for blocking the flow, is a ball. In some ball check valves, the ball is spring-loaded which keeps the ball in a sealed position. Designs without a spring need the flow in the pipeline to be reversed, the friction of the fluid along with the weight of the ball will move the ball towards the seat and create a seal.
When to use a ball check valve ?
The first criteria is that you need to flow to be stopped when it is reversed. Ball check valves are often very small, simple, and cheap making them a good economical choice. The balls in these valves are often made of metal but, they can be made of other materials. In some rare and specialized cases they have been made out of highly durable or inert materials, such as sapphire.