Which NSTM pertains to O-rings?

The choice regarding NSTM (Naval Ship’s Technical Manual) pertaining to O-rings is based on the specific guidelines and technical information it contains about sealing devices. NSTM 078 specifically focuses on the topics related to seals, gaskets, and O-rings utilized in various systems within naval operations. This manual provides detailed instructions on the selection, installation, maintenance, and testing of these components to ensure effective sealing and prevent leaks. Understanding the specifications and proper handling of O-rings is critical, particularly in undersea conditions where pressure and environmental factors can greatly affect performance and safety. Thus, choosing NSTM 078 is correct because it directly addresses the relevant technical guidance for O-rings.