Ball Valves

View A Video on Ball Valves- A Quick Introduction

Ball valve manufacturers produce valves with two primary design options: floating ball and a trunnion. A floating ball valve uses a non-fixed ball to drift into place against the seat, providing a tight seal. A trunnion fixes the ball in a certain place and is used for more complicated applications and, therefore, is more costly. The handle, which can be motorized, actuated or manual rotates the ball a one-quarter turn. When the hole of the ball is facing away from the pipe opening, flow is restricted. When it is aligned with the opening, flow is restored. The position of the handle immediately indicates whether the valve is closed or open. Ball valves are manufactured from a variety of materials, the most common being stainless steel, brass, cast iron and plastic (like PVC). The size of ball valves can also vary. Mini ball valves are usually less than an inch in diameter and are therefore used in hard to reach areas or in confined spaces. 3-way and flanged ball valves are variations in ball valve manufacturing. Ball check valves allow liquids to flow in only one direction and high pressure ball valves allow low and high flows of pressure and temperatures.

Along with being easy to monitor, ball valves are also simple to clean and repair; as the ball rotates, the seat performs a self-wiping action that prevents any buildup. The type of application determines which ball valve is the most appropriate. Ball valves are used in many different industries because of their ability to provide operators with control and complete shut-off capabilities. They can be used for isolation of systems, regulation of some types of low flow and backflow prevention but only with a swing check component. Ball valves are used with pipes but can also be found in tools, equipment and tubing systems across almost every industry that uses pipes to transport gases, liquids, and suspended solids. Ball valves can be manual or motorized. Instead of requiring manual operation, actuated ball valves are opened and closed by a power actuator that sits on top of the valve and provides the necessary force and motion to operate remotely or automatically. Motorized ball valves use a motor instead of a manual actuator to open and close the valve which is beneficial for certain valves.

Stainless steel ball valves are designed for use in demanding applications where corrosion resistance is imperative. Brass ball valves are manufactured by casting brass, a metal alloyed from copper and zinc. PVC ball valves are constructed from a polymer of vinyl chloride and offer outstanding resistance to water, chemicals and concentrated acids. 3-way ball valves have three ports through which flow passes. It is controlled in the way that flow comes in one inlet and can come out either or both outlets or, if the handle is rotated, flow can be shut-off completely. The outside edges of flanged ball valves are raised into a flange and have holes appropriately placed for bolting the valve in between pipes. These valves are convenient because they are simple to add or remove to a piping system. Another useful style of ball valve is the ball check valve, also referred to as a non-return valve. In ball check valves, liquids can flow in only one direction. High pressure ball valves are able to meet even the most demanding applications and can handle small and large flows with high pressure and temperature ratings. Sizes of ball valves range from fractions of an inch to multiple yards in diameter and up to 7,500 psi in pressure ratings.

Advances in ball valve design and materials have significantly increased their popularity. New valve designs have enabled ball valves to be used in high-vacuum situations. This possibility was not previously considered, due to the inherent tendencies of these valves to leak and trap gas. Ball valve suppliers will also be able to offer aluminum construction in the near future. The ability of throttling is being developed as well and is in fact already possible with some ball valves. Throttling allows operators to use the ball valve to allow some fluids to pass through the valve at a restricted flow. Other recent innovations and improvements have led ball valves to experience minimal wearing when open. Full port valves have zero wear because the hole in the ball is the same diameter of the pipes so the valve is flush inside. There are no internal components that retain debris and, while some ball valves do trap small volumes of fluid in the hole as they rotate, certain models purge that space to prevent this from happening. Blowout proof stems guarantee safety even when the valve is under high stress because the stem that holds the ball inside the valve enclosure is able to withstand high pressure and temperature instead of shooting from the valve.

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Ball Valve Types

• 3 way ball valves have three different ports. Some three way valves have all ports open while others may all be closed or only have one open.
• Actuated ball valves are not operated manually, but rather automatic power actuators.
• Ball check valves are valves where liquids can flow only one way. The pressure from the liquid forces the ball to move, when the pressure from the fluid stops the ball also stops and the valve closes.
  
• Ball valve manufacturers make various kinds of ball valves.
• Brass ball valves are valves made from brass, one of the most common materials for ball valves.
• Flanged ball valves have raised edges that allow these valves to be easily added, accessed or removed.
• Floating ball valves do not use a stationary ball but rather allow the ball to move a small distance to increase the contact area with the primary seat.
• High pressure ball valves can handle small and large flows with high pressure ratings.
• Mini ball valves are very small valves that use a rotating ball to create a seal.
• Motorized ball valves are engaged by an electric motor instead of being manually operated.
• Plug valves are quarter-turn valves which utilize a cylindrical or tapered plug with a hole in the middle to control flow.
  
• PVC ball valves are made of a polymer of vinyl chloride.
  
• Stainless steel ball valves are made of stainless steel.
  
• Swing check valves use outside levers to slow down the flow of materials through a pipe. The lever pulls the ball into the flow which causes the flow to stop more quickly.
  
• Two way valves have an inlet pipe connection and an outlet pipe connection.

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Ball Valve Terms Actuator - Used to operate the ball valve. The actuator is often used to control the flow of materials. Ball - The closure portion of the valve that restricts or controls the liquid or gas flow. Butterfly Valve - A valve that utilizes a circular disc or vane in order to control flow by turning the valve's pivot axis at 901/4 angles to the pipe's flow direction. Flange - A projecting rim or edge used to strengthen or attach one object to another. Full Bore Value - The diameter of the ball inside the valve equals the diameter of the pipe. This is also called full port.   Globe Valve - A globular shaped valve whose internal moving parts consist of the disk, the valve stem and the hand wheel.   Poppet Valve - A valve that moves up to or from its seat perpendicularly. This valve generally provides more flow than a ball valve.   Port - Flow path.   Pressure Control Valve - A valve that controls the amount of pressure. Typically the valve will shut when a pre-determined pressure is reached.   Pressure Relief Valve - A valve that releases pressure if needed. This valve is self-operating.   PSI (Pounds Per Square Inch) - A unit of pressure; equivalent to the metric unit of Kilonewtons per square centimeter.   Reduced Bore Value - The ball inside the valve has a hole smaller than the opening in the pipe, allowing for better control. This is also called standard bore or port.   Relief Valve - A valve that when open allows for the release of excess pressure or temperature.   Slurry - A mixture of liquid, typically water, and solid materials to create a material similar in consistency to mud or plaster of Paris.   Trunnion - Upper and lower supports used to keep the ball under pressure.   Valve Seat - A stationary part of the valve which restricts liquid or gas flow when it comes in contact with the movable portion of the valve.

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