What’s the difference between a 2 line pressure tank with the cap screwed on tight and a 6 gallon single line steel OMC tank sitting in the sun with the vent screw tightly closed? I will tell you. The 2 line pressure tank will vent to the atmosphere when the 4 to 6 pound pressure moves the relief check valve off it’s seat. The single line tank will continue to build pressure beyond that. Looking to see when a tank explodes from pressure is not a realistic concern with a properly functional and maintained tank. Either tank set up if it built to much pressure would just push the carburetor needle seat off it’s seat and gas would leak out of the carburetor vent. It’s funny 2 line pressure tanks were never an issue till the single line tanks came out. The only problem with a 2 line tank is that they are 60 years old now and would be mechanics do not understand how they work and half ass try to fix them and do not know how to test them and get mad at them when it does not work right. To bad nobody wrote to that show Myth Busters and asked the to do a comparison of safety and pressure. Would have been an interesting show. Regards Bill,
Sorry, I beg to differ. The metal single hose tanks had a pressure relief valve too. Items 26, 27, 17.
