IEC IEEE 61886-1-2021 pdf download.Subsea equipment – Part 1: Power connectors, penetrators and jumper assemblies with rated voltage from 3 kV (U max = 3,6 kV) to 30 kV (U max = 36 kV).
12.2 Absorption/compensation test
12.2.1 Objective This test is to determine the compensation and ageing characteristics of a conduit hose filled with insulating oil and immersed in sea water at rated absolute pressure. Ageing is accelerated using high temperature. This test is also used to determine the amount of volume that the hose can compensate.
12.2.2 Method A hose assembly consisting of at least a two-metre length of hose, a pressure transducer (for monitoring hose internal pressure) and end caps shall be filled with the relevant compensation fluid and pressurised to the specified internal pressure. The dielectric strength and water content of the compensation fluid shall be recorded prior to the test. The hose termination fittings shall be identical to the type used in production jumper assemblies. The assembly shall be placed within a pressure vessel and pressurised according to the test pressure below. For sea water applications, the test parameters shall be: – vessel fluid: artificial sea water as defined in 6.3; – vessel fluid temperature: 60 °C; – test pressure: 1 ,1 · RAP. For applications in other fluids or at other temperatures, the assembly shall be tested in the relevant fluid according to Table 8 at the worst-case conditions defined by Table 4; in this case, the test parameters shall be agreed between the manufacturer and purchaser. Monitor and record the following parameters daily over a period of 1 4 days (336 h): – vessel pressure; – internal hose pressure; – vessel temperature. A calculation shall be performed to determine how much uncompensated volume per length the hose can compensate throughout the pressure and temperature range. Electronic data storage or a chart recorder with a suitable number of channels is preferred to record the values. The recording shall be set up to detect any large deviation in the conditions of the test and to detect any important intermittent deviation in the recorded results. Alternatively, manual instruments with recordings at the beginning and at the end of each working day are required. At the end of the test period, the hose shall be allowed to return to ambient temperature, the vessel pressure shall be released, and the assembly removed from the test vessel. The hose shall be inspected for damage and defects. The dielectric strength and water content of the compensation fluid shall be recorded after the test and compared with the results obtained prior to the test, to evaluate if there has been a significant degradation in the insulating properties of the fluid.
12.2.3 Acceptance criteria
a) The hose shall be free from damage or defects. All observations shall be documented within the type test report.
b) The dielectric strength of the compensating fluid within the hose shall be measured by means of breakdown voltage and volume resistivity. These figures shall not change more than 5 % from original values to denote no water ingress.
c) No free water shall be observed.
d) A net positive pressure shall be maintained within the hose throughout the test duration.IEC IEEE 61886-1 pdf download.