A new holistic solution is designed to remove varnish deposits and keep turbines running efficiently

For maintenance and operational personnel, achieving trouble-free operation while keeping maintenance costs as low as possible is a constant balancing act, particularly given the huge financial impact caused by unexpected turbine downtime.

When forced outages in a power plant are turbine related, a percentage of those outages are contributed to by the lube oil system, where the underlying cause is varnish. Even the smallest amount of varnish in a system can result in erratic component operation such as valve sticking, poor heat exchanger performance and even bearing failure. These problems also lead to a shortened oil life and loss of equipment productivity.

Many engineers believe that varnish can only be managed by continuous varnish filtration and a combination of mechanical and chemical cleaning during planned downtime. However, what is often missed is that using varnish filtration and standard cleaning practices to remove varnish is often not effective, especially on severe varnish that has been depositing for years in both hot spots and cooler areas of equipment.

These issues needed an approach that could keep existing turbine systems running, limiting unnecessary shutdowns, equipment failures and the resulting inefficiencies. Texaco’s Vartech technology provides a new method designed to not only clean a running system but also to keep it clean and deposit-free over time, helping to achieve optimum productivity of a plant’s turbines. The technology is designed to work as a holistic two-step clean-and-control solution to help operators reduce the threats of varnish.

Step 1: Industrial System Cleaner

The advanced chemistry in this product allows operators to substantially clean existing varnish out of their equipment system to prepare it for fresh oil. Vartech industrial system cleaner is designed to dissolve varnish deposits from internal surfaces and then stabilise them in the oil for removal with the used oil. In extensive testing it has shown greater varnish cleaning effectiveness and improved oil and seal compatibility compared to many alternative cleaning approaches.

Step 2: Selected Turbine Oils

The freshly cleaned system is then filled with the appropriate GST Advantage turbine oil for the operation. Texaco lubricants formulated with Vartech technology help limit the precursors that can precipitate out of oil leading to varnish formation. 

And finally, to ensure ongoing system performance, Texaco provides a specialised oil condition monitoring programme (LubeWatch) in which in-depth varnish analysis can be performed on a regular basis.

Paul Sly, global industrial OEM specialist comments: “We are all fully aware that the lost revenue caused by unplanned or longer than expected shut down can be extensive. Our challenge was to create a solution that moved away from relying on varnish filtration and dated cleaning methods.

“The utilisation of the Vartech two-step programme, in conjunction with our LubeWatch monitoring has seen companies successfully change their maintenance process to remove any deposited varnish more effectively before they fill their systems with new oil. Our holistic varnish solution has shown strong deposit removal effectiveness and deposit resistance with GST Advantage Turbine oil products in extensive comparative laboratory and field testing. This improves system deposit control and cleanliness, delivering longer oil life and helping optimise turbine operation.”