What is a Ball Valve?

A ball valve is a shut-off valve that controls the flow of fluids. It consists of a valve body in which a sphere with a central hole is mounted. By rotating the ball, 90 degrees around its axis, the medium can flow through or is blocked. They have a long service life and provide a reliable sealing over the life span. They are more common as a shut-off valve then the gate valve. Moreover, they are more resistant to contaminated media than most other types of valves. In special operations, ball valves are also used as a control valve but have relatively limited accuracy of controlling the flow rate in comparison with other types of control valves.

Standard (threaded)

Standard ball valves consist of the housing, ball, and lever for ball rotation. They are most common and come in many varieties based on their applications, mini ball valves, angled ball valves, valves with an integrated strainer (bleed point), etc. They are available in a wide range of options and an operating range for pressure and temperature.

Hydraulic

Hydraulic ball valves are specially designed for hydraulic and heating systems due to their high operating pressure and heating oil resistance.   The seats are made of polyoxymethylene, which is suitable for high pressure and low-temperature applications. The maximum operating condition goes above 500 bar and 80°C.

Flanged

Flanged ball valves are specified by their connection type. The ports are connected to a piping system via flanges that are usually designed per a certain standard. They provide a high flow as they have a full-bore design. They are usually made out of steel, stainless steel, or cast iron.

Housing materials

The most common housing materials for ball valves are brass and stainless steel. The ball is usually made of chrome-plated steel, chrome-plated brass, or stainless steel. The seats are often made of Teflon, but could also be made of other materials.

Brass ball valve

Brass valves are the most popular in the field. Brass is an alloy of zinc and copper has excellent mechanical properties. Brass valves are mostly used for potable water, gas, oil, air, and many other media. Chloride solutions may cause dezincification which left a porous structure that decreases mechanical strength. A brass housing is ideal for an airball valve.

Stainless Steel ball valve

Stainless steel ball valves are used for corrosive environments. They are mostly used in seawater, swimming pools, high temperatures, and many chemicals. Most stainless steel is austenitic. They are characterized by their types, 304 and 316 are the most common. 304 is commonly referred to as 18/8 because of 18% chromium and 8% nickel. 316 has 18% chromium and 10% nickel (18/10).