6.3Operation of the Emergency Vent. Valve
The emergency vent. valve is opened immediately after an abnormality/error in the magnetic bearing, excessive vibration or any other abnormality/error is found. Gases (dry N2 gases or other) are introduced through the emergency vent. valve into the STP pump. Attach the emergency vent. valve taking care of the following NOTICE:
NOTICE
◇It is recommended to introduce dry N2 gases to prevent the STP pump and vacuum equipment from getting contaminated.
◇The allowable gas pressure ranges from zero [atmospheric pressure] to
4.9x104Pa [gauge pressure] (zero [atmospheric pressure] to 0.5kgf/cm2 [gauge pressure]).
◇The rotor comes into contact with the touch down bearing, with the emergency vent. valve opened. This may damage the rotor or the touch down bearing. To stop the STP pump in a very short time, design an appropriate vacuum exhaust system that closes the vacuum valve at the outlet port flange when the emergency vent. valve is opened.
This prevents the rotor and the touch down bearing from being damaged.
◇The state of the emergency vent. valve can be checked using "DC I/O TB3 L. VALVE N. O. OUT Terminal
