Generally speaking, the purpose of a specifically vented ball in a ball valve remains the creation of a flow path that will allow the trapped service medium a means of egress from the isolated cavity created inside the valve when the ball rotates into the closed position.13 Oct 2020
What is a vented ball on a ball valve?
What is a Vented Ball? NIBCO stainless steel balls have a feature commonly referred to as a vented ball. This feature is simply a hole in the ball which allows most fluids or gas trapped in the cavity between the ball and valve body to escape.31 Jan 2019
What is a venting valve?
The vent valve is a device installed to prevent negative pressure (e. g. as a result of surge pressures) in a piping system. Vent valves are also installed at the highest points in a piping system downstream of shut-off elements or pumps, and at the highest points in domestic installation systems. Venturi tube.
How many types of ball valves are there?
Types. There are five general body styles of ball valves: single body, three-piece body, split body, top entry, and welded. The difference is based on how the pieces of the valve—especially the casing that contains the ball itself—are manufactured and assembled.
Why ball valves are not used in steam service?
Ball valves, like all valves, are generally rated at a lower pressure for steam service than for liquid or dry gaseous service. Wet steam is damaging to all valve parts at the moment of opening and closing, or when throttling. This results in stem and ball corrosion, unless the valve materials are properly selected.
Why is it called a ball valve?
A ball valve is a shut off valve that controls the flow of a liquid or gas by means of a rotary ball having a bore. By rotating the ball a quarter turn (90 degrees) around its axis, the medium can flow through or is blocked. As a result, they are more popular as a shut off valve then for example the gate valve.
What is a ball valve in plumbing?
Ball valves, also called shut-off valves, tend to be increasingly found in newer homes. Ball valves use a handle to control the placement of a hollow, perforated sphere in the mechanism. When the handle is turned, the hole immediately opens or closes the water flow.
How does vented ball valve work?
When the valve is open, system fluids flow through the valve. The vent passage allows pressure inside the valve to remain equal to system pressure. When the valve is closed, the vent passage faces downstream, allowing pressure to equalize between the body and the downstream system.
How does ball valve open and close?
Ball valves use a metal ball with a hole bored through the center, sandwiched between two seats to control flow. Ball valves do not use a handwheel, but instead use a wrench to control the flow. A 90° turn of the wrench opens or closes the valve.