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调节阀的流量特性是用来表示调节阀的阀芯在每个相对行程上,与通过调节阀的相对流量之间的关系的,正确地选择调节阀的流量特性,是调节阀应用的重要组成部分。一、固有流量特性流量特性是用曲线表示阀杆在不同位置(即不同开度)时通过阀的流量大小,很明显,通过调节阀的流量是要受到调节阀压力降影响,所以压力降是阀流量特性的特殊组成部分。一般调节阀制造厂提供的流量特性曲线或阀相对开度与相对流量的数据表,均是在调节阀相应固定压降条件下得出的。这种在固定压降下来求得的特性,叫做固有流量特性,有直线、等百分比(对数)、快开、抛物线四种,如图1所示。图中:(1)直线;(2)等百分比;(3)快开;(4)抛物线。以上四种特性是国内外采用较多的,除这四种以外,国外还有平方根特性,双曲线特性等。 1.直线流量特性直线流量特性是指调节阀的相对开度与相对流量成直线关系:
Flow characteristics of the control valve is used to represent the valve spool in each relative stroke, and the relative flow through the control valve, the correct choice of the flow characteristics of the control valve is an important component of the control valve application section. First, the inherent flow characteristics Flow characteristics of the valve stem is represented in different positions (ie, different degrees) through the valve flow rate, it is clear that the flow through the control valve is subject to the control valve pressure drop, so the pressure drop is Valve flow characteristics of the special components. General regulating valve manufacturer to provide the flow characteristics of the valve or valve relative opening and the relative flow of the data sheet, are in the control valve under the conditions of a fixed pressure drop derived. This fixed pressure drop to find the characteristics, called the inherent flow characteristics, a straight line, such as the percentage (logarithm), fast open, parabolic four, as shown in Figure 1. In the figure: (1) straight line; (2) equal percentage; (3) quick opening; (4) parabola. The above four characteristics are used more at home and abroad, in addition to the four outside, there are square root of foreign characteristics, hyperbolic characteristics. 1. Linear flow characteristics Linear flow characteristics refers to the relative opening of the control valve and the relative flow into a linear relationship: