Minnesota Boiler License Practice Exam

Which type of boiler typically operates under lower pressure systems?

1. High-pressure boiler

2. Low-pressure boiler

3. Steam boiler

4. Condensing boiler

The correct answer is: Low-pressure boiler

Low-pressure boilers are specifically designed to operate at lower pressure systems, typically defined as boilers that provide steam or hot water at pressures not exceeding 15 psi for steam and 30 psi for hot water. This classification means they are commonly used in residential heating, small commercial applications, and for processes that do not require high-pressure steam. The pressure is a critical factor in determining the type of boiler necessary for a given application; low-pressure boilers are less complex and have lower safety risks compared to high-pressure systems. They are often easier to operate and maintain while providing adequate heating and hot water for various applications without requiring the stringent controls and safety systems needed for higher pressure operations. In contrast, high-pressure boilers are built to operate at significantly higher pressures, catering to industrial processes that demand steam at elevated levels. Steam boilers can operate at both high and low pressures, making them a broader category that includes both types. Condensing boilers specifically focus on improving efficiency by recovering heat from exhaust gases, but they can also be designed for low pressure. Therefore, the focus on the minimal operating pressure directly aligns with the defining characteristics of low-pressure boilers.