The Front End Valve (FEV) is used to isolate the User's beamline vacuum and the Front End vacuum. It has been designed with a special viton seal to allow for fast closing and a heavier duty cycle. This valve is interlocked by the Front End Equipment Protection System (FE-EPS). The FE-EPS will close the valve if it detects that the vacuum on the User's beamline has risen above a set vacuum threshold.