The Exposure Test evaluates the effects of gas permeation, gas decompression and test fluid exposure at rated temperature of choke and kill flexible lines. The test fluid is oil (diesel), brine water and gas composed of methane, carbon dioxid and hydrogen-sulfide. The working pressure is between 345-1380 bar, the working temperature is between 82-130°C depending on the line’s type. The test starts when the line is in the protecting tube assembled and filled with the test fluid. The line is pressurized three times to rated working pressure and rated temperature. The first pressurization lasts for 24 hours, the second and third for 12 hours each. Between each pressurization there is an hour resting time. Following the three pressurizations the flexible line is examined, and retention of the internal diameter is checked by gauge test. If the line maintains its minimum ID, then the test can proceed with the line’s pressurization to rated working pressure and rated temperature and hold for seven days. After the seven days exposure the line is cooled down to room temperature but the pressure maintained at rated working pressure for 30 days. Following the 30 days the line is pressurized with water to at least the test pressure for 30 min. For acceptance the line should not have any damage affecting normal usage.
Flexible line test station