Full scale rotary seal testing for oilfield rotary control devices (RCDs)

Kalsi Engineering has been performing rotary seal testing since 1979, to better meet the needs of our customers. In the past, much of the RCD-related testing was performed with small diameter seals. Our newest test fixture is sized for testing 10.50” ID seals used to retain high pressure in rotary control devices (RCDs). The fixture tests a pair of rotary seals at a time, at pressures up to 3,500 psi. The lubricant pressure is supplied between the pair of seals, so that each seal simulates the high pressure rotary seal location of an RCD. For ease of assembly, the fixture is based on our stacked housing design, which is shown in handbook chapters D17, E2, E4, E5, and E6. The fixture is easily adaptable to testing high pressure hydraulic swivel seals by swapping out inexpensive seal carriers.

This fixture began its inaugural run on May 23, 2016. Our test engineer and technicians assembled and instrumented the fixture so well that what we thought would merely be an instrument debug run turned out to be a useful test run!

This fixture allows us to test high pressure RCD seals on a rotating mandrel that approximates the thermal mass of the mandrel of an actual RCD. The fixture is modular, and easily adapted to test various types of RCD seals and various housing-to-mandrel clearances. This video shows the fixture in operation.

We built this fixture in order to test with a mandrel that approximates the thermal mass of an actual RCD mandrel. This will allow us to perform more realistic comparisons of the speed and pressure capabilities of various rotary seal designs. Toward this objective, we have purchased tooling to manufacture several different styles of 10.5” RCD seals.

The initial test was performed with seal carriers that are fixed in place radially. These carriers can be changed out rapidly to test with any desired extrusion gap clearance. The fixture also accepts our patented floating backup ring design. Although we plan to perform most of our testing without a circulating coolant, the fixture is easily adaptable to circulation of a coolant outboard of the test seals.

The fixture is driven by a 34 horsepower variable speed motor with a right angle gear drive and an in-line torque sensor. The data acquisition system monitors and records rotary speed, running torque, hydrodynamic pumping related leakage, lubricant pressure, and relevant temperatures. The system also provides for automatic shutdown if data exceeds predetermined limits, which allows the fixture to safely operate continuously without human intervention.

Our seal testing laboratory includes a total of seven rotary test fixtures, and is staffed by two technicians, a testing engineer, and a technician trainee. In an average year, they perform over 12,000 hours of rotary testing. Their efforts are directed by a group of engineers having a combined total of over 90 years of experience with Kalsi Engineering’s rotary seal technology.

Our significant investment in testing personnel and facilities allows us to compare the performance of newer seal geometries and materials to older ones, and to evaluate various hardware implementations, in a continual pursuit of increased rotary seal performance and reliability. Contact Kalsi Engineering for additional information on our high pressure RCD seals. For size availability, see our shaft seal catalog.

The design, assembly and instrumenting of our fixture for testing high pressure RCD seals was so successful that what commenced as a fixture shakedown test ended up being a useful R&D test