propane tank issue when used

swapped my 20 pound propane tank at the corner market for a full one and i am wondering if the valve is different because with the on/off gas flow twist knob fully closed and attaching this hose the propane instantly starts and will not stop flowing until hose fitting is unscrewed - the on/off twist knob valve is rendered useless! - if you buy this hose be sure to connect to tank LAST or the gas will empty itself threw the other end

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