New Method for Comparing Flow in Spring-Loaded Valves

Abstract

Abstract

Spring-loaded valves possesses a dynamic operating range, in which the moving element is balanced by the flow and the spring forces. This feature means that the valve performance, including the pressure drop coefficient and the valve gaps, cannot be fully described only by using the Reynolds number without considering the spring properties. In this article, the theoretical analysis of the flow in spring-loaded valves was made to unify the flow and the spring forces. A new dimensionless number named the Zhang number was defined, with which the valve gaps and thus the pressure drop coefficient in the dynamic operating range can be clearly described. The similarity of flows in the valve loaded by different spring sets is then ensured. The significance of this similarity has been excellently demonstrated by an industrial compressor valve. Specifically, once a valve loaded by a set of springs is characterized, the valve characteristics using other spring sets can be directly obtained from the existing characteristic. No additional calibration of valve flows is necessary.