Parts of a Ball valve

What is Ball Valve?

A ball valve is a type of plug that has a ball-shaped closing member. The flow of liquid or gas is controlled by a pivoting ball fixed in the center of the valve controls. The pivoting ball is called a rotary ball, It is designed with a central hole (a bore). There is a stem on the top of the ball rotates that is used to open or close the valve. The stem can be controlled manually or automatically.

Parts of a Butterfly valve

Gate Valve Parts

Types of Ball valve

Based on the number of body pieces

  • Single Piece
  • Two Piece
  • Three Piece

Based on flow ways

  • Two Way
  • Three Way
  • Four Way

Based on ball support

  • Floating Type
  • Trunnion Type

Based on ball entry

  • Side Entry
  • Top Entry

What are the parts of the ball valve?

  • Handle
  • Stem
  • Valve Body
  • Gland Nut
  • Inlet Port
  • Outlet Port
  • Ball
  • Body
  • Thrust Washer
  • Joint Gasket
  • Cap

Valve Body

This is the major section of the valve and contains all of the on/off control components.


The handle turns a ball in the valve that has a hole or port through it. If the hole is parallel to the pipe, flow continues through the valve; if the hole is perpendicular to the pipe, the flow stops at the valve.


The stem is the shaft that links the internal ball to the outside of the valve to allow the ball to rotate.

Gland Nut

The gland nut compresses the packing material, forming a watertight seal and preventing water from seeping up the shaft when the tap is turned on. To accommodate continuous operation, the gland at the spinning shaft of a centrifugal pump may be packed similarly and graphite grease employed.

The bushing of a gland or glands is the section of a valve that holds or compresses the stem packing in a stuffing box.

Inlet Port and Outlet Port

A valve with an inlet port connected to one part of the system and an outlet port connected to another part of the system, is set so that the fluid medium is blocked from flowing to the outlet port until the inlet pressure increases over the preset opening pressure.


These are the discs that sit between your body and the ball. Seats act as a barrier between the two and also support the ball.


The Bonnet is the valve’s second pressure-retaining component. It is also known as a cover. We can make a valve enclosure by bolting, welding, or threading it to the system.

The aperture in the gate, stop, or diaphragm wall allows the valve stream to flow through. Bonnet allows access to the internals of the valve during maintenance.


The valve body is the primary pressure-retaining component, and it also houses the disc and stem. This also allows flow from the valve; its end connection is pipe; this end can be welding type, threaded, or a variety of others depending on the size and pressure of the piping system.

Depending on the application, the valve body can be cast or forged in a variety of materials such as cast steel, stainless steel, and alloy steel.

Thrust Washer

Thrust washers are flat washers used to connect a revolving surface to a stationary component. They support the axial load or side-to-side motion on a shaft while also preventing movement along that shaft. The thrust washer provides a surface for a bearing to rest on.

Joint Gasket

A gasket is a fundamental component of flanged connections in a plant’s piping system. A gasket is a sealing substance or a mixture of materials clamped between two separate mechanical elements of a mechanical joint (flanged joint) that provides the connection’s weakest link.

Applications of Ball Valve

Ball valves are mainly used in a wide range of applications, from the home to specialised industries. Consider the following examples:

Dishwashers, washing machines, and outdoor hoses

Oil and gas industries, automotive, power processing, pharmaceutical, etc.

Advantages and Disadvantages of Ball Valve

Advantages of Ball Valve

  • Low-pressure drop and minimal leaking
  • They are compact and may be opened quickly.
  • It is suitable for rapid quarter-turn on-off action.
  • Low torque tight sealing
  • Low cost and long service life

Disadvantages of Ball Valve

  • If the seat is utilised for throttling, it will wear out.
  • Quick opening may result in a hammer.
  • Suspended particles can settle in ball valves when they are used for slurries or other purposes, causing the valve to fail.