Abstract: A joint comprising a main seal, a secondary seal and an external pressure test port providing access to a cavity between the main seal and the secondary seal wherein the integrity of the main seal can be tested in its in-service direction by applying pressure to the cavity via the pressure test port such that the cavity is pressurised and the main seal is tested. Following testing of the main seal, the secondary seal may become redundant during normal use of the joint. In some embodiments, however, the integrity of the main seal can be retested at any time due to the reusability of the secondary seal.