Technician’s Suggestion Saves Utility Time & Money

EPUD Generation Plant Specialist Jason Rice with Caterpillar 3516 internal combustion engine at Short Mountain Methane Power Plant.

With more than 25 years of experience working on heavy equipment, and 15 years working specifically with the engines at Emerald People's Utility District's (EPUD’s) Methane Power Plant, Generation Plant Specialist Jason Rice really knows his equipment. So well, in fact, that when he identified a problem with a part and suggested a manufacturing fix directly to Caterpillar, he quickly got their attention.

Emerald’s Methane Power Plant at Short Mountain Landfill employs four large Caterpillar 3516 internal combustion engines to burn landfill gas and generate electricity. In this harsh environment, each of the engines has two water-cooled exhaust manifolds that are expected to be replaced regularly; however, they have repeatedly failed prematurely and without warning. These failures are costly and cause devastating damage by flooding coolant into the cylinders and engine. It costs up to $30,000 to replace the two manifolds, but the utility also loses generation hours and must pay up to 36 man-hours to restore the engine to working condition.

Over the years, Rice studied the exhaust manifold and kept detailed records of his tests and findings. Early on, he identified that the air shield was fabricated from mild steel, making it less resistant to chemical corrosion than stainless steel. In hopes of convincing Caterpillar to adjust their manufacturing process, he wrote a 34-page report that included many photos of the corroded parts, diagrams pinpointing where the component failed, and a dated log of the replacements, failures, and the widely varied and unpredictable run-time hours before failure. He submitted the report to the local Caterpillar dealer, Peterson CAT, but it quickly found its way to Caterpillar’s corporate headquarters.

Following a Customer Product Improvement Zoom meeting with Caterpillar’s engineers, a custom exhaust manifold with a stainless steel air shield was made for Emerald and installed on one side of an engine. At the same time, a new manifold with a regular mild steel air shield was installed on the other side. In November 2020, after 10 months of use, Caterpillar collected both components to be tested. A short time later, in February 2021, they announced that the new water-cooled exhaust manifolds used in the 3516 engines were altered, changing ‘the inner shell of the manifold to stainless steel to help prevent premature corrosion.”

“It’s exciting to have been involved in correcting the part, an improvement that’s beneficial for everyone involved,” said Rice. “I look forward to seeing the results first-hand.”