At United Equipment Accessories’ Alpha location in Texas, we recently were asked to supply an independently pressure compensated slip ring for an underwater winch. For subsea applications, pressure compensation is required to keep the pressure between the subsea environment and internal system consistent. Using pressure compensation, the system applies a pressure equal to the pressure in the external environment. Typically, our slip rings are integrated to a standalone pressure compensator but in some system configurations, the slip ring needs to be independently pressure compensated.
We used a Pressure Balanced Oil Filled (PBOF) cable on one side of the slip ring, to serve as the compensating reservoir, and a bulkhead connector on the other side. We filled the slip ring and PBOF cable fully with oil, completely removing all air from the system. A 1-way valve and a purge valve are used to ensure that the unit is filled with oil and slightly over pressurized (~5-10 PSI). The amount of oil needed for the reservoir is dependent on the depth and temperature range of operation. The volume of oil contained in the 3 ft long PBOF cable is over 90% of the volume of the slip ring, which is ample compensating volume for essentially any water depth.
This slip ring is sealed to keep the seawater out and oil in the system, with a sealing level rating of IP68. The slip ring enclosure is made of 316 stainless steel, which is industry standard for subsea applications.
UEA can customize the circuits in the slip ring to match the requirements for the customer. This specific slip ring required three circuits for power at 400 VDC and 2.5 amps and 4 circuits for signals.
UEA can help you create a custom slip ring solution for your subsea application. Each part of the slip ring from the size to the circuits to sealing can be designed to your specifications. Contact us today to create your solution today!