Reducing valves specified herein are intended for pressure reducing service in air or nitrogen systems in Naval ships. They may be used in an Emergency Air Breathing (EAB) System where they are not the last valve in a series or cascade valve arrangement, and the guidance and selection requirements of MIL-HDBK-227 have been applied. This includes use of manual bypass valves and use of the priority side of an air system where appropriate. This specification does not include miniature or high precision pressure reducing valves generally associated with instrument or life support applications.