I would doubt whether the problem is liquid carryover unless you have significant damage to some of the first few impellers. The gas should be hot and dry by the time it gets to the balance drum. What about the binder and bonding material compatibility with your gas ? As a last resort, other type balance piston seals should be available from the OEM, but may effect performance slightly if not as "tight". I'd talk with the OEM if you have not already done so.