I'm probably the only one on the website who hadn't figured this out. Year after year at inspection time I sweated getting the bowl off my blue Vans gascolator. Even with the sump valve opened vapor lock wouldn't let go. Today it occurred to me to remove the plug at the top and use my compressed air nozzle to pressurize it. Pow! Came off with authority! Next time I'll adjust the regulator down to about 5psi. John