Ball Valve

A ball valve is a valve with a spherical disc, the part of the valve which controls the flow through it. The sphere has a hole, or port, through the middle so that when the port is in line with both ends of the valve, flow will occur. When the valve is closed, the hole is perpendicular to the ends of the valve, and flow is blocked. The handle or lever will be inline with the port position letting you "see" the valve's position. The ball valve, along with the butterfly valve and plug valve, are part of the family of quarter turn valves.

  • Ball valves are durable and usually work to achieve perfect shutoff even after years of disuse.
  • The body of ball valves may be made of metal, plastic or metal with a ceramic center
  • Ball valves are used extensively in industrial applications because they are very versatile, supporting pressures up to 1000 bar and temperatures up to 482°F (250°C)

Based on body

one-piece ball valve

Single Piece

Single-piece ball valves are installed as a unit. The retainer holds the ball and seal. Compression of the seal is controlled by increasing or decreasing the tightness of the threading holding the retainer. A single-piece ball valve must balance the integrity of the seal against the friction between the ball and seal. If the retainer fails to secure the entire seal, the pipe forces will be uneven and the seal will wear unevenly.

two-piece ball valve

Double Piece

Two-piece ball valves allow for easier assembly. The body is split into two pieces and the configuration uses a floating ball. The two body pieces are combined with a flange and bolts. This design makes servicing the valve easy and the procedure can be done in-line. The disadvantage of a two-piece valve design is the seal tightness can be altered by the system force and temperature, creating a potential leak path at the joint.

three-piece ball valve

Three Piece

Three-piece ball valves offer easy and fast access for valve maintenance. The three-body connector can be removed and the fourth can be loosened to allow the body to swing away to carry out installation or maintenance.