Minnesota Boiler License Practice Exam

For a coil type (fire tube) boiler over 500 square feet, how many safety valves are required?

1. One or more safety valves

2. Two or more safety valves

3. Three or more safety valves

4. No safety valves are required

The correct answer is: Two or more safety valves

In the context of a coil type (fire tube) boiler with a heating surface greater than 500 square feet, the requirement for safety valves is critical for ensuring the safe operation of the boiler. Safety valves are essential safety devices designed to prevent excessive pressure build-up within the boiler, which could lead to dangerous situations such as explosions or equipment failure. When the heating surface area exceeds 500 square feet, the regulations mandate the installation of a minimum of two safety valves. This requirement is in place to ensure redundancy; if one valve fails or is undergoing maintenance, the second valve can still function, maintaining safe operating conditions. The rationale behind requiring more than one safety valve for larger boilers is based on the increased risk associated with higher pressure and larger volume systems. The additional valve helps to ensure that, in the event of a malfunction or failure of one valve, there is still a backup in place. For smaller boilers (those with a heating surface of 500 square feet or less), one safety valve may be sufficient, reflecting the lower risk level. However, as the size and potential hazards of the system increase, so do the safety requirements to protect both the equipment and personnel.