Smart Gasket : Steam Seal Integrity Monitor

Client: US Navy (NAVAIR Lakehurst)


Challenge:

The Low-Loss Launch Valve is a large (multi-ton) steam valve integrated into Navy aircraft carriers as part of the steam catapult system.  Scheduled maintenance of the valve requires removal and retooling at Lakehurst NAS, with a very high cost to disassemble and transport.  A sensor system that allows condition-based maintenance based on the seal integrity could save the Navy millions of dollars annually.  However, the failure point is sealed inside the valve with no easy access point and in an extreme heat and humidity environment.

Figure: Solid model of LLLV (left) and stress analysis showing failure of LLLV seal (right)

Solution:

TA implemented a multiple approach engineering study, starting with a comprehensive modeling effort to fully understand the failure modes of the LLLV.  A number of technologies were applied, including the use of ductile sensor leads that could be compressed beyond the flatness rating of the flange faces while still maintaining insulation integrity and conductivity.  However, TA showed through modeling, that the failure modes of the valve could be reliably detected from outside the valve.  Therefore, a uniquely developed inductive displacement sensor could be applied to the outside of the valve, greatly simplifying installation and data & power connections.