Study and application for LNG facilities of 36%-Ni steel with a very small coefficient of linear thermal expansion.

A 36%-Ni steel, which is generally called "Invar", is the ideal material for a 20% cost reduction in construction of LNG piping as compared to LNG piping made with 18-8 stainless steel (SS304). This is because there is no need for loops and because the diameter of the LNG piping is smaller, providing a reduction of the pressure loss in long and large diameter piping. The reason for these is that the coefficient of linear thermal expansion of 36%-Ni steel is very low; only about 1/10 of the coefficient of 18-8 stainless steel. This sophisticated technology has been proven to be problem-free when applied to the construction and operation of a 32-inch LNG unloading line and a 16-inch LNG send-out line at the Ohgishima LNG receiving terminal operated by Tokyo Gas. The conclusion is that 36%-Ni steel should replace 18-8 stainless steel as a new material for LNG facilities.