[EricH]

If it isn't listed in R77, it isn't legal. That said, solenoids are fairly wide open--take a look at R77C, R77D, and R75--but also R74, which simply says that if it isn't listed, it can't be used.


Now, as for the second question: You have two pressures. Pressure #1 includes the compressor, pressure sensor, vent valve, at least one gauge, and as many storage tanks as you care to have at 120 psi--and a regulator. Figure 4-15 from R78 may be helpful here.

Pressure #2, on the other side of that regulator, is at 60 psi, and includes a gauge and however many solenoids and cylinders you happen to be using, possibly including more storage tanks and possibly some regulators as well.

Oh, and there IS a rule on this. R83 is what you were missing--it's a list of what can be at 120 psi. There are no cylinders or solenoids in that list.