Tanabe H-264 air compressor water contamination into sump oil


Hello everybody,
In my ship one compressor which is a Tanabe H-264 series-
It’s a 2 cylinder two stage tandem type compressor with attached water pump.
This is having water contamination into the sump oil.I tried changing the cylinder head gasket and inter cooler and after cooler gasket but still have water presence after running the compressor.If the compressor is kept idle there is no trace of water leaking into the sump.And I also opened the water outlet pipe and use air pressure to pressurize the water chambers but still there is no trace of water leaking into the sump.
Can anyone please help me giving some idea how to find the leakage or how to rectify that?


Your compressor has an attached water pump? Depending on how this is driven off the crankshaft perhaps a leaking shaft seal between pump casing and compressor sump?


Dear sir,
I am attaching the cooling water pump drawing here.
FYI,this has a drain pipe in between the oil seal and shaft lubrication
So,I suppose if have any leaking shaft seal then water must be coming out
through the drain pipe and that’s the problem…I do not find anywhere
water leaking from


Is it a lot of water? Could it be condensation if it’s not happening when the compressor is kept idling?


Is the tell tail drain on the seal clogged? If it is, the water leakage can push it’s way into the oil side.


The water contamination is 0.22% as I checked the L.O. with onboard L.O.
test kit.


The compressor is kept idle for long time but there was no trace of water
So, I suppose water leakage is only during running time


What kind of oil are you using with this machine? You prolly know that air compressors required special oil, with special water properties… I’m just wondering.


Currently using Mobil Rarus 827 synthetic oil


While compressing your high humidity air a fair amount of water accumulates in the discharge areas of the coolers. I do not know your type of compressor but most modern types have solenoid valves in their discharge lines which are opening in certain intervals to drain the accumulated water off with a short burst.
It happens that the solenoid isn’t correctly working and an overload of humidity is kept in the circuit sneaking through the ring gaps into the oil. Check your drain intervals.


Thank you very much for your reply.
May be this is the solution to my problem as my compressor model Tanabe H
series is a 90’s model and this doesn’t have any solenoid v/v as you
mentioned.So, as I checked everything else I suppose this problem is
because of the humidity and also the leakage of the piston pin seal disk as
I found a considerably large amount of water in the chamber when I opened
the 2nd stage suction and delivery v/v’s.


To verify this hint please check the amount of drain water in your starting air bottles or wherever
the compressed air is stored. Drain your compressors in high humidity areas at least every hour.
Good luck.


Since your compressor is an older one, any one of the water passages, mating journals, or heat exchange cooling devices could be compromised by corrosion if the coolant was not always maintained properly, and leak from there into the crankcase. Especially if this only happens if the unit is running. Sometimes a threaded bolt hole into the oil sump body or block was drilled out too deeply and finally begins to leak. Sometimes you can get lucky making a repair on a badly exposed surface by cleaning it with strong solvents and then either brazing the fault or repairing with an epoxy compound. You are only trying to stop a low pressure water leak.
You could be reacting too strongly to a merely incidental amount of water contamination, although there certainly should be none, in a perfect world. Some oil sumps are protected by a breather that has humidity-absorbing dessicant filters attached. The coolant could be causing condensation inside the sump from the humidity-laden air entering the crank case area. Condensate drains on an intercooler or final cooler can not only be blocked, but maybe some genius who preceded you on the ship re-routed a drain pipe into the oil sump! Since you have already done a lot of troubleshooting to learn where your problem really is, you can’t dismiss even the most outrageous possibility!




assuming you’ve done the usual stuff … as seadjon said: a blind hole that is no longer blind being rusted out, or re-drilled too deep to use a EZ out … these can be a bastard and unless you’ve encountered one before not likely to be discovered on your first tear down. otherwise: those 1/4" and less… and bigger, drainlines get plugged all the time. oh yea. check for water entering the air intake… i encountered this though i don’t recall what it was on but that was a sneaky bitch to figure out!


masad rama; let us know what you figure out ok? trouble shooting is after all like forensics!!!