New research by Sandvik’s R & D organization has confirmed the benefits of using Sandvik Hiflex(tm) strip steel for the manufacture of flapper valves for compressors. Sandvik Hiflex(tm) is a new generation of martensitic stainless chromium strip steel and a modified AISI 420 type material. Flapper valves are one of the most important components in compressors used, for example, in automotive air conditioning systems and in refrigerators. Fundamentally a spring made from pre-hardened steel, flapper valves are subjected to very high cyclic loads as the valve opens and shuts. In order to meet industry’s demands a flapper valve steel with high impact fatigue strength must have a high tensile strength, high ductility and high damping capacity. Hiflex has all of these properties. It is particularly suitable for use in applications with a high valve lift and in carbon dioxide compressors for automotive air conditioning, where high temperatures and pressures exist and place heavy demands on the valve material. Its stainless steel metallurgy means that Sandvik Hiflex is also suitable where corrosion resistance is required.
