What does Boiler installer license class 4B allow a contractor to install?

The Boiler installer license class 4B specifically permits a contractor to install boilers with a capacity not exceeding 300,000 pounds of steam per hour. This classification is designed to ensure that contractors working on larger boilers possess the necessary expertise and knowledge regarding safety standards, installation procedures, and maintenance.

This limit is significant because it distinguishes between various classes of boilers and prevents unqualified individuals from working on high-capacity systems that require more extensive technical knowledge and adherence to regulations. By allowing the installation of boilers up to this capacity, the licensing ensures that contractors can effectively manage the complexities involved in working with larger, potentially more dangerous systems.

The other options suggest either broader or different scopes of installation that fall outside the specification of a class 4B license. For instance, allowing installation of any capacity boiler or solely nuclear heat source boilers require different qualifications and knowledge that may not align with the scope of training for a 4B license.