What are the four types of ball valves?

A ball valve is a flow control device that uses a hollow, perforated, rotatable ball to control the fluid flowing through it. The ball is open when the hole is in line with the inlet, and closed when it is rotated 90 degrees by the valve handle, blocking the flow of water. When opened, the handle is placed flat in line with the flow of water, and perpendicular to the flow of water when closed for visual confirmation of the state of the valve. Closing position 1/4 turn can be clockwise or counterclockwise.

Ball valves are durable, perform well after many cycles, and are reliable enough to safely close even after long periods of use. These qualities make them the best choice for shutoff and control applications, where they are generally preferred over gate and globe valves, but where they lack the fine control of these alternatives in throttling applications.

The ease of operation, maintainability and versatility of ball valves make them widely used in industry, supporting up to 1000 bar (100 mpa; 15,000 pounds per square inch) and temperatures up to 752°F (400 ° C). Sizes typically range from 0.2 to 48 inches (5.1 to 1219.2 mm). The valve body is made of metal, plastic or metal with ceramic; Float balls are usually chrome plated for durability. A disadvantage of ball valves is that when used to control flow, they trap water in the central cavity in the closed position. At ambient temperatures below freezing, the sides may crack due to expansion associated with ice formation. [3] In such cases, some insulation or insulation usually prevents damage. Another option for colder climates is the "freeze proof ball valve". This type of ball valve has an antifreeze plug installed on the side so that in the event of freezing, the antifreeze plug will break as a "sacrificial" point of failure, making repair easier. There is no need to replace the entire valve, just install a new antifreeze plug.

If the ball valve is used for low temperatures or products that may expand in the ball, there is a drilled vent upstream of the valve. This is called an air ball.

Ball valves should not be confused with "ball check valves," which use a solid ball to prevent unwanted backflow.

Other types of quarter turn valves include butterfly valves, plug valves, and antifreeze ball valves.

Ball valves generally come in five body styles: 1pc ball valve, 2pc ball valve, split, jacked and welded. The difference is based on how the various parts of the valve -- in particular, the housing that contains the ball itself -- are made and assembled. Valve operation is the same in each case.

The one-piece body provides a very robust construction, and in some versions the ball can be removed from the valve without the whole [clarification] coming off the line, but the multi-piece body provides more room for design ingenuity.

In addition, there are different styles related to the aperture of the ball mechanism itself. And according to the different working pressure, ball valve can be divided into low-pressure ball valve and high-pressure ball valve. In most industries, ball valves with operating pressures above 3,000 psi are considered high pressure ball valves. Typically, high-pressure ball valves have a maximum operating pressure of 7,500 psi, up to 15,000 psi depending on construction, size and sealing material. High pressure ball valves are often used in high pressure applications such as hydraulic systems, so they are also called hydraulic ball valves.

Ball valves up to 2 inches in size are generally available in one -, two - or three-piece designs. One-piece ball valves are almost reduced diameter, the price is relatively cheap, are generally thrown away. Two-piece ball valves are generally slightly reduced in caliber (or standard), and they can be thrown away or repaired. The three-piece design allows the center portion of the valve containing the ball, stem and seat to be easily removed from the pipe. This facilitates efficient sediment cleaning, replacement of seats and gland packing, and polishing of small scratches on the spheres, all without removing piping from the body. Three-piece valves are designed to be serviceable. Each valve is heated to a certain extent while excess material is trimmed from the body.