The term “severe service” has been used to develop new valve markets and even create popular new valve types, such as severe service ball valves. That term also has likely been misapplied as much as it has been correctly used.
If you are a process control operator in a plant, you might consider every energy-containing pipe run and valve to be severe service, since the results of a valve failure could be costly or hazardous to your health. Although virtually every valve contains potentially dangerous energy or controls potentially hazardous ﬂuid, the degrees of danger vary. These service criteria are used to determine the valve’s design or the robustness of a valve to safely handle a particular service application.