Hydrogel Activated Bulkhead Shaft Seal

Midé is proposing to complete the development of a hydrogel activated bulkhead shaft seal for the DDG-51 class ships. The purpose of a bulkhead seal is to prevent flooding between compartments along the main propulsion shafting. The current shipbuilder specifications require that the bulkhead shaft seal must be self-activating with a maximum leakage rate of 1 US pt/min for DDG ships. The problem is urgent given the failure of the USS Cole’s bulkhead shaft seal that resulted in engine room flooding. The reported flooding occurred at a rate of up to 15 GPM. In Phase I, Midé developed an innovative lip-seal solution. The Midé lip-seal has hydrogel foam that, when exposed to water, swells and deforms the lip of the seal to make contact with the shaft. Under normal conditions the seal is not in contact with the shaft and will not wear. In the base effort Midé plans to mature the Phase I technology to TRL6 through a deliberate development process that first optimizes elements in the design before a full-scale seal will be tested under the required (relevant) conditions. The Phase II Option effort will be to further mature the technology to TRL7 through sea trials.