A Globe Valve, different from ball valve, is a type of valve used for
regulating flow in a pipeline, consisting of a movable plug or disc element and a stationary ring seat in a generally
Globe Valves are named for their spherical body shape with the two halves
of the body being separated by an internal baffle. This has an opening that forms a seat onto which a
movable plug can be screwed in to close (or shut) the valve. The plug is also called a disc or disk.
In Globe Valves, the plug is connected to a stem which is operated by screw action using
a handwheel in manual valves. Typically, automated globe valves use smooth stems rather than threaded and are opened
and closed by an actuator assembly.
All valves are designed to meet a designated internal permissible leak rate standard (FCI/ANSI). There are six (6) permissible leak rates or Classes numbered 1 through VI. The higher the leak rate number, the lower permissible internal leak rate.
Identifying the permissible internal leak rate for a valve has to be one of the top priorities when choosing the correct valve. A valve with a high leak rate, will cause excessive wear. The valves with a high leak rate will internally pass more medium and result in premature valve failure.
There are six different seat leakage classifications as defined by ANSI FCI 70-2.