The primary function of a globe valve is for throttling, i.e. increasing or reducing the flow in the process as required.
The secondary function is isolation, where the flow can be fully fully stopped.
A third function is reduction. This can be achieved by designing the valve with an aperture in the seat area that is smaller than the line pipe diameter.
Globe valves are generally used for throttling operations. Operation of the valve is via a hand wheel or other manual or automatic operator. By turning the hand wheel, the stem rises, taking the plug further away from the seat, thus allowing larger flow aperture, for the process medium to pass through.
The seat to seal interface is normally created by a “plug” on the end of the stem forcing onto a screwed insert (or machined surface directly on the internal of the valve body). Energisation is by mechanical force applied through the hand wheel down through the screwed stem.
Globe valves can come in a number of configurations including straight, angled or oblique pattern. The design configuration affects the turbulence within the flow of the process and this is why these different configurations exists.