Which statement about nitrogen service gauge pressure is accurate?

• A. It is fixed at 160-185 psi
• B. It varies with system type
• C. It depends on ambient temperature
• D. It depends on altitude

Answer: (B)

The tested idea is that nitrogen service pressure is determined by how the system is built and what it serves, not by a single fixed value. In different installations—whether nitrogen is supplied from cylinders, bulk liquid tanks, or a pipeline network—the downstream devices and processes require different pressure and flow characteristics. Therefore the service gauge pressure is set by the system design and regulators to meet those specific needs, which is why it varies with system type. Temperature and altitude can affect gas density or readings in some cases, but the outlet pressure specified by the system remains the controlling factor, so those factors don’t fix a universal value.