Have never used the prime valve to load the line/gun for painting. I simply pull the trigger on the gun and turn the machine on. Sprays out the water or spirits in the line, about 1/3 gal. And the paint follows. If I run out of paint and lose prime I just put the paint in and pull the trigger and if it doesn’t prime I will isotherm prime valve. Here’s the problem with using the prime valve. The operator I.e. the painter cleans the hose and gun but forgets to flush out the prime valve thereby eventually clogging the prime valve. Ruined. Even cleaning it always a little residue that builds up over time. I have the same unit for years. Never replaced the prime valve.
Good info. I think I'll give this a try. I never understood why priming is needed if I plop the pickup hose in a bucket of paint, pull the spray gun trigger and turn on the machine. I always thought I could save time at setup and cleanup if I bypassed the prime valve.
