[hgs_notes]

For safety sake, replace the relief valve that is on the tank. If it's a thick tank it was probably rated at 200 psi. Whatever the nameplate rating is for MAWP is the highest you put on for relief valve setting. Some of the older tanks have odd MAWP ratings, like 137 psi. If it's running at 135 and that's adequate for you, then a 150 or 165 relief would be good. I've seen some 2 stage pumps that are running at 175 with 200 psi reliefs that are fine. The added pressure means there is more air volume in the tank and the compressor will recycle less often, but for a longer run time. If the tools are not rated for that pressure, just use an in-line regulator.