Specially formulated for the flapper valves of automotive and stationary air conditioning compressors, the new Sandvik HiflexTM stainless strip steel makes possible smaller, more efficient compressor designs. It is of particular interest to producers of CO2 compressors using high discharge pressures. The flapper valve regulates the flow of refrigerant gas to and from the compressor through suction and exhaust valves. As such, it is subjected to high cyclical loads and impact stresses. One of the most important components in an air conditioning system, it is a spring made from pre-hardened steel.
The new Sandvik Hiflex stainless strip steel offers increased tensile strength and improved toughness. It has more than 10% greater bending fatigue strength and 25% improvement in impact fatigue resistance when compared with conventional and commonly used flapper valve stainless steels. It enables compressor designers to miniaturise compressors, use thinner valve flaps, increase reliability, or boost compressor efficiency with greater valve lift. The increase in bending fatigue strength is made possible through the increased tensile strength of the material. The impact stress resistance is improved both by the increased tensile strength and by a substantially higher internal damping capacity.
Sandvik Hiflex has a bending fatigue strength of ± 120psi and a maximum allowable impact velocity of 12.5 meters per second (41 feet per second). It enables designers to reduce the size of valves and compressors by using shorter valve tongues to achieve the same valve lift. In addition, the new steel allows increased valve lift in order to reduce pressure drop across the valve and boost compressor efficiency. Thinner valve flaps can reduce mechanical losses. The new steel can also be used to improve the reliability of existing valves prone to fatigue failures.
