actually Tx Bill, if you hook it all up and
then turn on the water [1/4 turn], you've got "air over hydraulic"
and I'd be sure that folks using original valves from years when the cooling system was
zero pressure, on systems that have been modified to
15# don't have valves blowing up

works for me
64fleetside - there was a lot of grief in town when they "upgraded" the water system - some folks didn't pay any attention to the warning that regulators should be installed, blew out old water heaters among other things, but my place was plumbed by me with a 1" feedline for commercial, no problems here with 70#, and great for the apple processing biz
and Stoo, the hose tap in front of my house is before the regulator
Bill