Ball Valves

Ball Valves are a form of quarter-turn valve that uses a hollow, perforated, and pivoting ball to control flow through it.  It is open when the ball’s hole is in line with the flow.  It is closed when it is pivoted 90 degrees by the valve handle. 

The handle lies flat in alignment with the flow when open, and is perpendicular to it when closed.  This makes for easy visual confirmation of the valve’s status.

Ball valves in sizes up to 2 inches generally come in single-piece, two or three-piece designs.  One-piece ball valves are almost always reduced bore, are relatively inexpensive, and generally are throw-away. 

Two-piece ball valves are generally slightly reduced (or standard) bore, they can be either throw-away or repairable.  The 3 piece design allows for the center part of the valve containing the ball, stem & seats to be easily removed from the pipeline.

This facilitates efficient cleaning of deposited sediments and replacement of seats and gland packings.  It is also used for polishing out small scratches on the ball.   All this without removing the pipes from the valve body. 

The design concept of a three-piece valve is for it to be repairable.

Full port

A full port more commonly known as a full bore ball valve has an over-sized ball.  This is so that the hole in the ball is the same size as the pipeline resulting in lower friction loss. 

Flow is unrestricted but the valve is larger and more expensive so this is only used where free flow is required.  This is for example in pipelines that require pigging.

Reduced port or reduced bore

In Reduced port (more commonly known as reduced bore) ball valves, flow through the valve is one pipe size smaller than the valve’s pipe size resulting in the flow area being smaller than a pipe.  

Sanitary Valve Series Brochure