Lube oil leaks

A closed-loop refrigerant condenser ought to be one of the cleanest services in a process plant. Even seal- or lube-oil leaks affect the evaporator efficiency, rather than the condenser. I have measured rather high [e.g., 140 Btu/[(h)(ft2)(°F)] heat-transfer coefficients in such condensers, even after that condenser has been in service for several years since its last cleaning. 

At startup, turboexpander lube oil leaked into the stripper feed and plugged the column. The NRU was shut down, and a hydrocarbon solvent was used to dean the system. 

Table 5.21 Failure Modes Continued Vessels Lube oil leaks in...

On occasion, evaporator deficiencies can be due to compressor lube oil leaking into the refrigerant. The lube oil will accumulate in the bottom... 

A closed-loop refrigerant condenser ought to be one of the cleanest services in a process plant. Even seal- or lube-oil leaks affect the evaporator efficiency, rather than the condenser. I have measured... 

TROUBLE EXCESSIVE CARBON ON VALVES PROBABLE CAUSE(S) 1. Excessive lube oil. 2. Improper lube oil (too light, high carbon residue). 3. Oil carryover from inlet system or previous stage. 4. Broken or leaking valves causing high temperature. 5. Excessive temperature due to high pressure ratio across cylinders. 

Leak in discharge piping. Lube oil temperature or gummy deposits in bearings. 

Defective grouting. 2. Leak in lube oil cooler tubes or tube-sheet. 

Some large motors have their lubricating oil cooled by cooling tower water. If the bearings on these motors go out frequently, check the lube oil for water. The small lube-oil coolers may be leaking due to corrosive cooling tower water. On one unit this problem was solved by retubing the coolers with 316 stainless steel. 

Oil Release to the Columbia River. On February 6, 1987, approximately 19 L (5 gal) of turbine oil was discharged to the Columbia River through the 182-N tank farm raw water return line. A small (pin-hole size) leak in a lube oil line in the No. 2 drive turbine allowed oil to enter the secondary steam system. Steam condensate from this system returns to the lOO-N steam condensate system that drains to the river. The leak in the lube line was repaired (DOE-RL 1990). 

Lube Oil Line Leak 5 gal of turbine oil. Pinhole leak in lube oil line allowed oil to enter secondary steam system. Discharge to river with steam condensate. 

The contact seal can be used under 1,000 psig. It is more complex, but has the advantage of not leaking while shut down. The contact seal is used extensively in refrigeration service where the compressor is part of a closed loop, and the shutdown feature is desirable. As mentioned, the seals must have a source of cooling and buffer fluid. In many cases, this fluid is lubricating oil. If contamination is not a problem, a combined lube and seal system can be used. 

The hydrostatic testing is the first test used on the lube system. The system is tested while assembled or partially assembled, based on the particular system. A test pressure of VA times the maximum allowable working pressure, a minimum of 20 psi for the oil side, is used for the test. For the oil-wetted parts, the test fluid should be light oil, which is normally the recommended lubricant for the compressor train. The test period is the length of time needed to inspect for leaks, or a minimum ol thirty minutes. Acceptance is based on the lack of leaks as visually observed or the lack of a drop in the test pressure. 

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