NFPA-99 Practice Exam

What is a requirement for regulators in a bulk cryogenic supply system containing parallel pipe duplex line regulators?

1. A balanced design

2. Check valves on the source side of each regulator

3. Each regulator sized for 110 percent of the peak calculated demand

4. Made of stainless steel

The correct answer is: A balanced design

A balanced design is a key requirement for regulators in a bulk cryogenic supply system containing parallel pipe duplex line regulators. This design ensures that the regulators operate efficiently and can share the load evenly between them. It helps in maintaining consistent pressure across the system, which is crucial for the safe and reliable delivery of cryogenic gases. A balanced design mitigates the risk of one regulator being overworked while the other is underutilized, which can lead to system failures or inefficiencies. In contrast, while check valves on the source side of each regulator can be beneficial for preventing backflow, they are not inherently a requirement of the parallel design. The sizing of each regulator for 110 percent of the peak calculated demand is a safety measure but does not directly relate to the parallel configuration's need for balance. Lastly, the material of the regulators being stainless steel is important for durability and resistance to corrosion but is not a foundational requirement tied specifically to the operational principles of parallel duplex line regulators in cryogenic systems.