This valve is a combined regulating and flow measurement device and must be installed with five diameters of straight pipe of the same diameter as the valve without intrusion upstream of the valve.

• 这种阀门组合了调节和流量测量的功能，必须安装在与阀门通径相同的五倍管道直径长度的直线管道地方，使其不受阀门上游的侵扰。