Class 5 Boiler Practice Exam

What is the maximum pressure allowed for hot water boilers installed by licensed journeyman plumbers according to ORS.480.634?

1. 100 psi

2. 150 psi

3. 200 psi

4. 250 psi

The correct answer is: 150 psi

The maximum pressure allowed for hot water boilers installed by licensed journeyman plumbers, as specified in ORS 480.634, is indeed set at 150 psi. This standard is established to ensure safety and operational efficiency within boiler systems. Hot water boilers must operate within safe pressure limits to prevent hazards such as overheating and potential explosions. A limit of 150 psi is typically considered appropriate because it helps to safeguard the system under normal operating conditions while allowing for a margin that accommodates variations in pressure due to thermal expansion and other operational factors. Exceeding this limit could lead to excessive stress on the components of the boiler, which may increase the risk of failure and safety incidents. In contrast, options indicating higher pressures (200 psi and 250 psi) exceed the safe thresholds established by regulations and would be impractical in typical installation scenarios by journeyman plumbers. Lower limits, such as 100 psi, do not provide the necessary capacity for most commercial and residential boiler operations, which can demand higher pressures for effective heating and distribution.