Just so you know....(many shops get this wrong as they don't deal with 1/2" taper valves as much these days)...
If the valve does not have specific wrench flats, always place the jaws of the wrench across the regulator yoke interface. Use the largest wrench you can find with jaws that are wide enough to cover the interface (o-ringed) surface. Do not place the jaws of the wrench on the sides of the valve as you chance bending the rim of the o-ring channel, damaging the regulator interface. It seems counterintuitive to have the jaw of a wrench on the surface you don't want to damage, but you want the jaw flat on the interface.
