Which agency typically governs the operation of high-pressure boilers?

The National Board of Boiler and Pressure Vessel Inspectors is the correct choice because it specifically focuses on the safety and regulation of boilers and pressure vessels. This organization provides oversight for the manufacture and operation of these systems, establishes standards for inspections, and ensures compliance with the relevant codes and regulations.

High-pressure boilers must adhere to strict guidelines to ensure the safety of their operation, and the National Board plays a key role in certifying that these standards are met across various jurisdictions. Their consistency in evaluating and certifying equipment helps prevent accidents and ensures that the designs and operational practices align with safety protocols.

The other agencies mentioned, while important in their respective fields, do not specifically govern the operational standards for high-pressure boilers. For instance, the Occupational Safety and Health Administration addresses workplace safety more broadly, the Environmental Protection Agency focuses on environmental protection and regulations rather than specifically on boiler safety, and the American Society of Mechanical Engineers provides standards and recommended practices but is not a governing body that enforces regulations on boiler operations.