Woodward valves and actuators must be stored and maintained according to manufacturer recommendations in order to ensure proper reliability, availability, and safety of operation.  Attached to this article are PDFs which detail these requirements.  Many users operate equipment outside the Woodward recommendations, but this leads to undesirable functionality when component life limits are reached.  Many common signs of poor storage/maintenance are leakage, difficulty controlling position, and valve sticking.

Note that the maintenance recommendations are based on normal operating conditions, environment, fuel quality, and past maintenance history.  Products in more demanding situations may need to be replaced more often and should have a customized maintenance cycle.  Contact your local Woodward representative to determine the right maintenance cycle for your installation.