This is a U.S. Navy solicitation for a **stem for a 2 1/2-inch ball valve**, designated as **SPECIAL EMPHASIS material** for use in a crucial shipboard system, with performance expected at a location to be specified by the offeror. The contract will be awarded on a **Lowest Price Technically Acceptable** basis and is a **Total Small Business Set-Aside** with a **DO-rated priority for national defense**. The contractor must maintain a quality system per **ISO-9001** and comply with extensive traceability, certification, and inspection requirements, including quantitative chemical and mechanical analysis. The material must be **mercury-free**, and all threads must be inspected per **FED-STD-H28**. The government will perform quality assurance at the source, and the contractor must submit a certificate of compliance for the special emphasis material.