Investigating complex matter requires custom-built equipment
Sealing matters have many different influencing parameters and it is difficult to determine the contribution of each individual parameter in traditional full-scale connection testing. OCAS therefore combined customer input and skills from various fields of its expertise into the design and manufacturing of a custom-built device to investigate sealing of metal-to-metal connections in more detail. Moreover, the sample dimensions and test conditions needed to be representative for industry.
To investigate the influence of surface topography and surface evolution during make-up a face-to-face sample configuration was selected. Tests have been carried out on samples with different radii, different surface finish and coatings using various lubricants subjected to representative loading conditions followed by pressurisation.
For highly challenging sealing situations seals can also undergo a certain evolution due to cyclic loading and/or thermal cycles after make-up. So, the equipment was designed to be able to test ball in cone contacts as well and simulate all of these aspects and allow for different variations providing a wide range of test conditions.
During a test, some sealing parameters such as gas or contact pressure are gradually altered until leakage occurs. Leaking gas is trapped inside a leak trapping chamber allowing a quantitative estimation of the effect on the leak rate.
Benefit from our sealing service offer
The test set-up offers the ability to investigate or compare
- Surface topography and evolution
- Coatings and lubrication including the effect of a thermal treatment
- Out of roundness of the initial samples
- Different contact pressures
Moreover, the onset of leakage and its exact location around the circumference can be determined bringing this test set-up to a much higher level than just a pass or fail test, and enabling a more precise comparison with numerical simulations.
”The developed test equipment really allows us to look at sealing-related problems from all angles, bringing this test set-up to a much higher level than just a pass or fail test.”
”From calculations to design, from drawings to technical file, from hydraulic system to software development for data logging, all aspects were handled by members of the engineering team, in close collaboration with many other OCAS departments. A nice example of great team work!”