Introduction:
Power plants, particularly nuclear power plants, require heat exchangers to cool down the primary working fluid for the power plant. Excessive vibration can lead to cracking and premature failure of the heat exchanger.

Problem:
A major power plant company approached MTI looking for a sensor that could measure vibration of a heat exchanger assembly that was immersed under water. Additionally, the water could reach 250 F and up to 220 PSI; the probe had to be sealed with a gland at a bulkhead feed through area.

Solution:
MTI developed a special fiber optic probe based on the MTI-2125H probe configuration. The probe was built with annealed stainless steel tubing, brazed at both ends; the sensing tip was then sealed with a special sapphire window and Viton o-ring, to create a pressure seal. Probe lengths were 180 inches, which enabled the probes to reach from the heat exchanger, through a Conax pressure gland, to the MTI-2100 fiber optic controller. Twenty-five probes were built and installed with no leaks and vibration is now continuously monitored.

Don’t let the pressure of a wet environment prevent you from choosing MTI Instruments sensors, our application engineers flourish when they can get their feet wet.