Dozens of detailed case studies on compressor and pump maintenance were a feature of last week’s Turbomachinery Symposium in Houston, Texas.
“The compressor rotor’s running position would suddenly change towards the axial thrust position, about 2.5 mm per month,” said Moll. “This happened after about six months to two years of stable operation.’
“We decided to do it in such a way as to avoid modification of the bearing housing as that would add cost,” she said.
“Our approach cost 10% of what it would have cost by resizing the balance piston,” said Moll.
Another case study at the symposium focused upon trip reduction in active magnetic bearings (AMB) in a turboexpander compressor being used by RasGas in Qatar. Two of the units in question were utilized for LNG and another for gas processing.
The automatic thrust balance system was not operating properly,” said Cencula. “We needed to reset it and change the logic of the system.”
“The source of the high frequency vibration is still to be determined,” said Cencula. “But there have been no trips for three years now.”