Steam Turbines

Since the inception of the first steam turbine used for generating power in the late 19th century, turbine oils have been at the root of surprisingly few failures. We have seen a reverse in this trend however as more steam turbine reliability problems are caused by turbine oils.

There are a few factors contributing to the rise in turbine oil problems:

  • Some new models of steam turbines place a higher amount of thermal loading on the lubricant, causing it to oxidize more rapidly than older steam turbines. In these units, varnish and sludge formation, particularly on the bearings can be a reliability risk.
  • Some industrial steam turbines have integrated controls with sensitive servo controls which are sensitive to varnish deposits.
  • Turbine oil formulations have changed over the last couple of decades. Most commercially available steam turbine oils have switched from a Group I to a Group II basestock utilizing advanced antioxidant chemistries. Although considerable improvements have been delivered with these new turbine oil formulations, problems have occurred when mixing older formulations with new formulations. Some of the fluid's properties. The bottom line is that today's steam turbine oils require different monitoring and maintenance technologies than have been used in the past.

Fluitec has a rich history of working with steam turbine oils and have developed the following unique solutions:

Condition Monitoring: The most common reason that steam turbine oils are changed is due to antioxidant depletion. Fluitec's RULER™ technology (ASTM D6971) is industry's preferred monitoring method to determine a steam turbine oil's Remaining Useful Life.

The most common physical change to in-service steam turbine oils is the formation of deposits as they oxidize and the antioxidants deplete. Fluitec's MPC Patch Kit test allows on-site determination of the fluid's deposit tendency (varnish potential). The Membrane Patch Colorimetry (MPC) test is standardized as ASTM D7843.

Maintenance and Contamination Control: Fluitec's Electrophysical Separation Process (ESP) technology is designed to remove turbine oil degradation products when they are formed, before they have an opportunity to develop into deposits. It is well understood that these degradation products (also referred to as soft contaminants) develop into deposits; however they can also cause addition problems in steam turbine oils. They are known to be catalyst which promote further degradation and shorter oil life. Their polar nature may also interfere with a turbine oil's water separability (demulsibility) characteristics. Use of Fluitec's ESP technology on steam turbine oils allows for deposit-free performance while also extending the remaining useful life of the fluid.

Many steam turbine controls are operated by a separate electro-hydraulic control (EHC) system utilizing a phosphate ester fire resistant fluid. Phosphate esters are hygroscopic and prone to water contamination. They also rapidly hydrolyze and deteriorate in the presence of water. Fluitec's Stealth EHC technology is the most cost effective technology available for maintaining very low water levels in your phosphate ester fluids.

Contact us today to learn how you can us improve your steam turbine reliability through Fluitec's knowledge and expertise.