The port of a valve is generally understood to be the connections that carry the flow of the liquid or gas into the valve and away from it. The valve port is also called valve bore. According to the different port sizes, there are full port valve, reduced port valve, standard port valve and V-port valve etc.

Commonly, the ball valves have such different port size valves, the port size in other types of valves tends not to vary; gate and globe valves are almost always full port by design. This is a result of their respective functions: Gate valves are simple shutoff and open valves incorporating a flat “gate” or disc across the port, while globe valves can throttle media flow while forcing it to alter its path through the valve. There is not much use for different port sizes in these types of valves.

However, there are occasionally non-full port gate and globe valves, particularly in oil and gas industries, but these are not common to use.