I was thinking about building an 'ultra' cheapo spunding valve system for pressure fermentation but leaving the pressure gauge out of it and just using one of these (plus some hose and a barb or two):
http://www.grainger.com/Grainger/CDI-CONTROL-DEVICES-Variable-Pressure-Relief-4TK26?Pid=search
Could I calibrate the position on the pressure relief valve (say to 20 psi) using my CO2 tank/regulator, and just leave the valve in position and use it without any kind of attached pressure gauge? The main problem I see is that the pressure marked on the valve is waaay inn inaccurate, but if I set it correctly once, it should work right? Why do people always add a pressure gauge to their setup?
http://www.grainger.com/Grainger/CDI-CONTROL-DEVICES-Variable-Pressure-Relief-4TK26?Pid=search
Could I calibrate the position on the pressure relief valve (say to 20 psi) using my CO2 tank/regulator, and just leave the valve in position and use it without any kind of attached pressure gauge? The main problem I see is that the pressure marked on the valve is waaay inn inaccurate, but if I set it correctly once, it should work right? Why do people always add a pressure gauge to their setup?