This interlock controls the X-1A valves according to vacuum conditions. It interacts with the front end interlock as described above, and with the X-1B interlock as described below. This interlock controls the X-1B valves. Besides protecting people and equipment, the interlock system allows one to open and close beamline pneumatic valves.
All crucial information pertaining to the interlock operation is shown on the unit's front panel.
If a valve does not open, it is because vacuum interlocks dictate otherwise. As a general rule, the only time an override switch should ever be on is during vacuum system maintenance or modification work. Note that all the VAT pneumatically-driven valves must be in the manually closed position for them to be able to be opened remotely by the interlock.