CORROSION OF NICKEL ALLOY 201 IN PRESSURE RELIEF DEVICES OF NATURAL GAS CYLINDERS

摘要

Several premature failures of nickel disks (Alloy 201) occurred in pressure-relief assemblies of natural gas cylinders. The mode of failure was intergranular corrosion by sulfuric acid, which was produced in the pressurized cylinder by oxidation and hydrolysis of trace hydrogen sulfide from the natural gas supply. The root cause of failure was excess residual moisture in the cylinders following hydrostatic testing.