原文：
      选择调节阀时，首先要收集完整的工艺流体的物理特性参数与调节阀的工作条件，主要流体的成份、温度、密度、粘度、正常流量、最大流量、最小流量、最大流量与最小流量下的进出口压力、最大压差等。而在技术方面主要掌握和确定调节阀本身的结构、流量特性、额定流量系数Kv值、口径大小、日标阀门工艺允许压差计算及执行机构的选择、材料和安装等方面的内容。 　选择调节阀时一般应遵循的原则有如下几点。

 　　一 调节阀的结构型式：应能满足介质温度、压力、流动性、流向、调节范围以及严密性的要求。

 　　二 调节阀的流量特性：应能满足系统特性进行合理的补偿。 　　调节阀的流量特性是指介质流过阀的相对流量与阀杆相对位移间的关系，数学表达式如下：Q/Qmax=f(l/L)，式中Q/Qmax为相对流量，英标阀门为调节阀在某一开度时流量Q与全开流量Qmax之比；l/L为相对位移，调节阀在某一开度时阀芯位移l与全开位移L之比。

 　　选择的总体原则是调节阀的流量特性应与调节对象特性及调节器特性相反，这样可使调节系统的综合特性接近于线性。德标阀门选择流量特性通常在工艺系统要求下进行，但是还要考虑下述实际情况。

 　　1、直线性流量特性适用范围：ISO国际标准阀门①差压变化小，几乎恒定；②工艺流程的主要参数的变化呈线性；③系统压力损失大部分分配在调节阀上(改变开度，阀上差压变化相对较小)；④外部干扰小，给定值变化小，可调范围要求小。

　　2、等百分比特性适用范围：①实际可调范围大；②开度变化，阀上差压变化相对较大；③管道系统压力损失大；④工艺系统负荷大幅度波动；⑤调节阀经常在小开度下运行。

　　3、除了以上两种常用的流量特性之外，美标阀门还有抛物线特性和快开特性等其他流量特性的调节阀。

 　　三 调节阀的口径：应能满足工艺上对流量的要求。 　　根据已知的流体条件，计算出必要的Kv值，选取合适的调节阀口径。

“ Control Valve Selection and Control of common sense ”是由中国调节阀网提供的国际阀门新闻，译文仅供参考。另外，中国调节阀网还提供相关产品搜索： CV3000调节阀、 电动调节阀、 执行器和附件、 更多调节阀产品、 调节阀价格等。

译文：
      Select regulating valve, the first craft to collect a complete physical parameters of fluid control valves and working conditions, the main fluid composition, temperature, density, viscosity, the normal flow rate, maximum flow, minimum flow, maximum flow and minimum flow rate import and export pressure, maximum pressure difference. In technical terms, and identify the main control valve itself, the structure, Filterflow characteristics, the rated flow coefficient Kv value, aperture size, process pressure difference calculation and the implementing agencies to allow the choice of materials and installation aspects. Select Valve when the generalBellow Seal Valve principles to be followed are as follows. The structure of a control valve type: should be able to meet the medium temperature, pressure, mobility, flow, adjust the scope and rigor requirements. Second, the flow control valve characteristics: the system should be able to meet the characteristics of reasonable compensation. Control valve flow characteristics is the medium flow through the valve stem relative flow and the relationship between the relative displacement, mathematical expressions are as follows: Q / Qmax = f (l / L), type in the Q / Qmax for the relative flow rate for the adjustment valve opening in a fully open when the flow rate Q and Qmax flow ratio; l / L for the relative displacement of the valve opening when the spool in a displacement L l and full-displacement ratio. Select the general principle is thatWater Pump Control Valves the flow control valve characteristics and regulation should be the object properties and regulator characteristics contrary, such a comprehensive feature can adjustForged Steel Valves the system close to linear. Select flow characteristics of the system requirements are usually carried out in the process, but also consider the following facts. 1, linear flow characteristics of the Needle Valvesscope of application: ① differential changes in small, almost constant; ② The main parameters of the change process is linear; ③ loss of most of the distribution system pressure regulating valve in the (change in opening the valve on the Pressure little change); ④ external interference is small, given the value of change is small, a small tuning range requirements. 2, the percentage of propertiesWater Power Control Valves such as the scope of application: ① the actual large adjustment; ② opening change, relatively large changes in differential pressure valve; ③ piping system pressure loss is large; ④ process system load fluctuations; ⑤ valve often in small opening run. 3, in addition to the flow characteristics of these two commonly used, there are parabolic features and characteristics of quick flow characteristics and other control valve. The caliber of three valves: should be able to meet the technical requirements on the traffic. Fluid under conditions known to calculate the necessary Kv value, select the appropriate valve diameter.

原文来源：http://www.1tiaojiefa.com/

2010-07-12 06:59

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