Flex-A-Seal’s Largest Split Cartridge Seal Seamlessly Installed at Hydro-Electric Plant

On July 26, 2017 Flex-A-Seal installed an 11-inch Style 85M split cartridge seal at one of the hydro-electric power generation facilities for Truckee Meadows Water Authority (TMWA) in Northern Nevada. As the largest split seal ever produced by Flex-A-Seal, the 11” seal solved a major challenge for the plant while saving the utility thousands of dollars in downtime and repair costs.

The Challenge

TMWA was moving gritty river water through an Allis Chalmers KH Water Turbine. The existing mechanical packing materials were contributing to extensive wear and severe damage to the turbine shaft. In addition, significant fluid leakage posed a hazard to the generator which was critical for operations.

The lengthy and involved process of replacing the mechanical packing was complicated by the turbine’s 15’ primary shaft. As a result, the operator was often left with a short mean time between failures (MTBF). The cost and downtime due to packing-related wear, as well as the manpower and expenses required to maintain the packing, negatively impacted the facility’s bottom line. These issues urgently needed to be addressed.

In this case, a standard cartridge seal installation wasn’t an option. Because of the turbine’s situational constraints, an alternative was needed that would provide the required sealing capabilities while also minimizing downtime and man hours for repairs.

The Solution

After extensive conversations with TMWA staff about their specific needs, goals, and challenges, Flex-A-Seal provided a complete solutions package:

  • Split adapter for easy installation on turbine
  • 11” Style 85M split cartridge mechanical seal
  • ORM (O-ring mount) split bearing/bushing with an API Plan 32 water flush
  • Silicon carbide hard faces

In total, the installation took three hours to complete – a fraction of the time required for mechanical packing maintenance. Installation time included site prep and equipment measurements, including concentricity and perpendicularity readings. The only materials needed for the installation were emery cloth and a shaft lubricant—no hoists were required despite the size of the equipment.

The Results

On-site after the installation, the seal had a smooth start-up and continues to run without issue.

The Flex-A-Seal solutions package solves many of TMWA’s concerns. The Flex-A-Seal Style 85M split cartridge seal addresses the sealing challenge of axial shaft movement under various loads. The O-ring mount bearing bushing solves the problem of excessive shaft runout, and the hard silicon carbide faces can withstand operation in sediment-laden river water.

Flex-A-Seal welcomed this opportunity to work with TMWA to provide a viable answer to their sealing challenge.

Thank you to the TMWA staff for their contributions to this article!

Watch a video of the 11” Style 85M Split Cartridge Seal in action!