The Department of Defense, specifically the Department of the Navy through NAVSUP Weapon Systems Support, is seeking proposals for the procurement of 55 units of a flight-critical valve, identified by NSN 7R-4820-015150545-QE. This procurement requires engineering source approval due to the unique design capabilities and manufacturing knowledge necessary to maintain the quality of the part, which is not readily available to the Government. Interested vendors must be approved sources or submit detailed information for source approval, as the contract will not be awarded without meeting qualification requirements. Proposals must be submitted within 45 days of this presolicitation notice, and interested parties can contact Gina P. Sassane at (215) 697-2198 or via email at GINA.P.SASSANE.CIV@US.NAVY.MIL for further information.