Siemens Go Up: gas in the tube oil, repeated membrane ruptures
What happened
Gas kept appearing in the Chronon tube oil system, and the oil pressurization membrane ruptured again a couple of months after an oil change, as reported in the case. HV arcing inside the tube was initially suspected.
What was checked
- Tube oil was replaced, but the problem returned, so the engineers looked for a source of gas generation in the oil system
- The oil circuit and the boost pump of the tube cooling system were inspected for air ingress
Cause
The engineers found that the boost pump was an open-type unit with a wet rotor, and its external motor nut had worked loose: air was being drawn in from under the rubber seal and carried into the oil circuit. The tube itself and HV arcing were not the cause in this case.
What was done
The engineers eliminated the air ingress: the loose external motor nut of the pump was tightened to restore the seal. In this case the gas problem did not recur after that.
Safety
Depressurise the oil boost circuit and let the tube cool before loosening any fittings, and return the scanner to clinical use only after high-voltage safety checks per the manufacturer's service documentation by authorised personnel.
Lesson: When gas keeps returning to tube oil after a fresh oil change, hunt for an air leak in the external circuit — pump, seals, fittings — before condemning the tube.
Covered in the course: CT Service — Level 2: Fault-Finding →
Written from an anonymised case shared by service engineers. It is not a manufacturer instruction and grants no authorisation. Independent note; names are trademarks of their owners.