A ball valve is a flow control device which uses a drilled ball to control flow of the medium.
The Pressure/vacuum relief valve Pressure/vacuum relief valve is an umbrella term that includes pressure or vacuum relief valve as well as pressure and vacuum relief valve. ball is moved via a handle or lever and turns inside the device Device A device is a pipe component that influences the media flow by opening, closing, or partially shutting off the flow channel or by dividing or mixing the media flow. , modulating the flow through the device.