EMAs

EMAs (Electrical Mechanical Actuaters) allow much greater control of valves. Instead of 
having a valve either open or closed, a valve can be commanded to intermediate positions 
such as 50% open. This can have a beneficial effect on start-stop transients. The EMAs are 
heavier than pneumatically actuated valves, causing an integration problem. A heavier valve 
on a line may cause stresses on the line that the pneumatically actuated valve did not 
cause.