Unloader

 
An unloader is used to deactivate an end of a cylinder. Valve plate depressor type suction valve unloaders are an example. Suction valve unloaders depress the valve plate to hold the valve open to unload the cylinder end. See “Cylinder Action, Single Acting for a drawing of a cylinder with a suction valve unloader.
 
 

Ariel Corporation Application Manual
18-Sep-96