Joel, Does your roaster have a pilot/safety valve? Mine does, rated to 1/2 psi, way less than the Clippard valve requires. If my EVP valve had worked, I would have needed a higher rated pilot / safety valve.

My 1K North roaster does not have a pilot safety valve seen on larger systems. It does have safety solenoid cut-off valve that only opens when the roaster is active and has an auto-reignition system if the flame blows out.

But this does beg the question how best to spec a proportional valve setup with larger capacity gas feeding systems. What kind of roaster do you have and does it offer a OEM automated option, and if so, how is it designed? Certainly larger systems must have already figured this out. In the the end, the secret sauce is not as much the valve choice (Clippard just worked out as low-cost solution for my roaster) but the Arduino duty/PID sketch and its integration with Artisan. Any solution that keeps the PID sketch largely intact to allow simple Artisan PID integration is where one needs to be for automation.

I went one step smaller in Clippard EVP valve (.04 orifice), but it was inadequate for the 500g Huky, open flame burner. I installed the pilot light configuration for the burner I use with my Huky.