What are Ball Valves

Professor Jim gives deep insights about the Ball Valve.
Open Ball Valve:
Ball is cushioned between 2 plastic, Teflon or O-ring seats which hold the ball in place
Unlike the metal to metal seats of a plug valve, resilient seats provide leak proof seals
Like the plug valve when the ball is rotated it also will have the port open
Water passes through the port in the ball
Closed ball valve
To close the ball vale you rotate 90 degrees or a Quarter turn
Port openings are now NOT in line with valve end openings
Fluid does not flow through the valve
Full port vs reduced port
Reduced – also known as a reduced bore valve has reduced port have the flow path through the valve one pipe size smaller than the original valve pipe size, resulting in flow area being smaller than pipe.
Full port or full bore – have an oversized ball so that the hole in the ball is the same size as the pipe; resulting in low pressure drop. These would be put in lines where free flow is required. Like a pipeline that requires pigging. Speaking of pigging that leads us to our did you know…
Did you know… that pigging is the action of cleaning a pipeline via the means of a device, that travels through the line, known as a pig. This device, an invention of the oil derived its funny name because of the squealing sound the original--composed of straw and wire--made as it traveled through a pipe.
Ball valve advantages – quick quarter turn on off operation gives a low torque on small sizes
Tight seal Reduce leakage – ball fits very well against the seat which reduces the chance of leakage
Most ball valves like Angelina jolie are bi sexual. Excuse me bi -directional which means These ball valves can be used in either direction.
Cost – the cost is lower then other valves
Disadvantage – no flow or throttle just like a gate valve. If you tried throttling it could damage the disk or the seat from the high velocity of flow. It should be used for on off applications only.
Midsize & larger valves have high torque – therefore they will need actuation
The seat is softer than the disk which helps the fit but makes it a bad valve for high temperature applications.