Come funziona la valvola a globo

In the globe valve body, there is a passage opening in the plane parallel to the flow axis and a globe valve is fixed on a moving threaded stem through a hinge in the plane perpendicular to the flow axis. The passage opening, flat closure, and stem are co-linear.

The threaded stem and the stationary nut in the globe valve body form a working pair.

The rotation of the stem is converted into its linear movement along the axis of the passage cross-section. In the extreme lower position, the stem closes the passage cross-section, and in the extreme upper position, it fully opens it.

The stem is usually sealed with a seal or less commonly with a bellows, and for globe valves in special designs, a diaphragm is used.

For a tight shut-off of the flow on the globe valve disc, PTFE or rubber gaskets are used, and in high-quality globe valves, the sealing is achieved by metal-to-metal contact through precise fitting of the globe valve and seat.

Globe valves with a stem perpendicular to the flow axis are called straight globe valves, while globe valves with an inclined stem are called angled globe valves and are characterized by lower hydraulic resistance compared to straight globe valves.

domanda : commento : feedback