Case Study – DuPont™ Kalrez® 0090 parts in a Pressurized Water Reactor System
DuPont™ Kalrez® parts yet again prove that they extend the service life of mechanical seals and process instruments!
One of the many uses of boiler feed pumps is as part of a Pressurized Water Reactor (PWR) system in nuclear power plants. In a PWR, the primary coolant (superheated water) is pumped under high pressure to the reactor core. The heated water then transfers thermal energy to a steam generator. The temperature and pressure of these pumps are typically 200°C and 3.5 MPa, with rapid gas decompression in some cases. Media is boiler feed water with dissolved oxygen, ammonia sodium salts, and hydrazine.
Due to the combination of extreme temperature, pressure, and chemical environments, an FFKM was used in a series of mechanical seals employed in the operation of boiler feed pumps for PWRs. However, the incumbent FFKM O-rings previously used showed signs of thermal and chemical degradation, as well as mechanical degradation. Cracks on the inside of the O-rings indicated that there was a high probability that the damage occurred at the time of a rapid gas decompression event when the pump was switched off. The lifetime of the seal was less than the required 18 months the customer had specified.
The customer then tested DuPont™ Kalrez® 0090 parts. Kalrez® 0090 parts offer an excellent combination of chemical, rapid gas decompression (RGD) resistance, and high-temperature resistance up to 250°C for O-ring applications in mechanical seals under these conditions. The use of Kalrez® 0090 parts and components can extend the MTBR (Mean Time Between Repair) of the pumps and reduce leakage which can translate into reduced maintenance costs and increased safety. Subsequently, the customer replaced all seals that were due for maintenance with Kalrez® 0090.
To know more about conversion to DuPont™ Kalrez® 0090 parts for your mechanical seals, contact our experts today!