Ball Valve - How They Work

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. They are characterized by a long service life and provide a reliable sealing over the life span, even when the valve is not in use for a long time. As a result, they are more popular as a shut off valve then for example the gate valve. For a complete comparison, read our ball valve vs ball valve article. ball valve are more resistant against contaminated media than most other types of valve.

In special versions, ball valve are also used as a control valve. This application is less common due to the relatively limited accuracy of controlling the flow rate in comparison with other types of control valves. However, the valve also offers some advantages here. For example, it still ensures a reliable sealing, even in the case of dirty media. Figure 1 shows a sectional view of a ball valve.

How Does a Ball valve Work?

Ball valve can have multiple ports, which are the openings in the valve. Two-way Ball valve have two ports and are used for traditional on/off control. Multi-port valves (3-way, 4-way, etc.) are used in applications that require more than one source of media or that need to divert media in different directions.

The port of a Ball valve can be opened or closed to control media either manually or through actuation. The manual option requires handles or levers and an operator to control the valve. Electric, hydraulic and pneumatic actuation don’t require an operator to control the valve. Actuation is ideal for complex control systems or those that are in remote areas that an operator cannot easily access.

Benefits of Ball valve

Compared to other types of valves, Ball valve offer several notable advantages:

--ompact, economical designs

--Fast shut-off speeds

--Durable in high-pressure, high-volume and high-temperature -applications

--Less prone to corrosion or damage

--Long service life

Versatile and ideal for a range of industrial applications Applications That Use Ball valve, Ball valve are used everywhere from around the home to specialized industries. Here’s a look at a few examples:

Home applications:

--Washing Machines

--Outdoor Hoses

--Dishwashers

Specialized industries:

--Oil & Gas

--Food & Beverage Equipment

--Automotive

--Vehicle Wash Systems

--Power Processing

--Pharmaceutical

--Chemical Admixtures & Treatment

--Irrigation & Water Treatment Equipment

--Manufacturing Facilities

--Parts of a Ball Valve

Ball valve are constructed with several crucial components:

--Ball valve

This is the main part of the valve and contains all of the components for on/off control.

--Rotary Ball

The ball is designed with a center bore (hole) that the media flows through. The direction of the ball is controlled by turning the stem.

--Stem

This connects the ball to the external control mechanism. For example, in a manual ball valve the stem is connected to a handle or lever.

--Seats

These are discs that lie in between the body and the ball. Seats provide a seal between the two and also support the ball.

--Power Source

The stem of the ball valve is rotated using manual or actuated power sources. Manual actuation includes levers and handles that are controlled by an operator. Automated power sources like electric, pneumatic and hydraulic actuation are also available.

--Packing

This is a seal around the stem that prevents the media from escaping.

--Bonnet

The bonnet is the part of the body that contains the stem and packing.