Sections G2418.4 & G2418.4.1 of the 2017 Oregon Residential Specialty Code (ORSC) and Sections C406.4 & C406.4.1 of the 2014 Oregon Mechanical Specialty Code (OMSC) state in part that, “….Mechanical gauges used to measure test pressures shall have a range such that the highest end of the scale is not greater than five times the test pressure.”
“Gas-piping systems under 14 inches water column (1/2# gas typ) shall be tested at a pressure not less than 10 pounds per square inch gauge. Test pressures shall be held for not less than 15 minutes with no perceptible drop in pressure. For welded piping and piping carrying gas at pressures exceeding 14 inches water column pressure (2# typ), the test pressure shall be at least 60 pounds per square inch for not less than 30 minutes.”
If the test gauge manufacturer wants a higher scale on their gauge to test a 60 psi pressure than an 80# gauge would be acceptable per the above code but it’s not a requirement in code that an 80# gauge is required. Usually we see 30# gauges on a ½# system and 60-90 psi gauges o the 2# systems.
Standard pressure gas lines need 12 psi for 15 min, 2lb gas lines need 60 psi for 15 min. so if you use a 30 Lb gauge you can leave it at 15 psi for standard pressure, if you use a 60 PSI gauge for 2 LB then you need to max it out at 60 PSI or use a 90 PSI gauge and put it at 65 PSI.