A method of protecting a hydrocarbon conduit during a period of reduced hydrocarbon flow is disclosed, where nitrogen is introduced into the conduit at a pressure of 1 to 350 bar g and at a rate of (1.5 to 35)A kg/sec (where A is the internal cross sectional area of the conduit in square meters) for a period of t hours where t=(p×d)/n where d is the length in km of the conduit from the nitrogen introduction location and n is 10 to 400.