What is the maximum outer diameter for NH3 gauge lines, and what is the pressure rating?

The correct option indicates that the maximum outer diameter for ammonia (NH3) gauge lines is 1/4 inch, with a pressure rating of 2000 psi. This specification is essential because ammonia, as a refrigerant and in various industrial processes, requires stringent safety regulations due to its hazardous nature.

The choice of a 1/4 inch diameter is standard for gauge lines to ensure proper measurement and safe handling within the specified pressure limits. A 2000 psi pressure rating provides a robust safety margin, accommodating the high pressures often encountered in ammonia systems while minimizing the risk of failures or leaks.

Understanding these specifications is crucial for professionals working with high-pressure systems, as they ensure both operational efficiency and safety. These parameters help prevent incidents that could arise from using inappropriate gauge line sizes or pressure ratings, thus maintaining compliance with safety standards in handling ammonia or similar substances.