After several years of development, Kalsi Engineering is pleased to announce a new line of 0.335” (8.51mm) cross-section Axially Constrained Seals: The 673 series. This new series offers improved abrasive exclusion performance over 462 series seals in conditions where the pressure of the abrasive environment is greater than the pressure of the seal lubricant. It is also compatible with lower viscosity lubricants than 462 series seals. Although it has a higher hydrodynamic pumping related leak rate than 462 series seals, the leak rate is still compatible with the reservoir size of many oilfield mud motor designs. Although the 673 series seal was developed for the same applications as the 462 series, and fits in the same groove, it was given a different series number because of the difference in leak rate.
The photo below shows a used example of a 673 series seal that was tested with a relatively low lubricant viscosity, and a rather high drilling fluid pressure, compared to the capabilities of a 462 series seal. The pressure of the drilling fluid was 90 psi greater than the pressure of the seal lubricant. The seal was tested with an ISO 150 viscosity grade lubricant at a bulk temperature of 162°F (72.2°C), simulating a targeted non-oilfield application. The shaft velocity was 288 feet per minute. As the photo shows, the used seal is in excellent condition following the ~100 hour test, with no abrasive invasion. This remarkable performance is attributed to the improved lubricating characteristics of the seal, and the more uniform deformation the seal experiences when exposed to differential pressure acting from the environment side.
Characterization tests of HNBR 673 series seals have been performed at temperatures as high as 300°F (150°C), and with lubricants ranging from ISO 150 to 680 viscosity grade. The seal design is also compatible with the -30 FKM material, for service up to 340°F (171.1°C). Contact us for additional information, so that you too can take advantage of this new advancement in rotary sealing.