GB / T 1047-2005 standard, the valve nominal diameter just a logo, represented by a combined symbol "DN" and numbers do not represent the nominal size of the valve diameter measured values, the actual diameter value of the valve consists of the standards-related provisions generally found (in mm) not less than 95% of the nominal value of size. Nominal size fraction Metric (symbol: DN) and imperial (symbol: NPS), GB valves metric, the US standard valve to English. Metric DN values ​​are as...

GB/T 1047-2005标准规定，阀门的公称通径只是一个标识，由符号“DN”和数字的组合表示，公称尺寸不能代表实测的阀门口径值，阀门的实际口径值由相关的各标准规定，一般实测值（单位mm）不得小于公称尺寸数值的95%。公称尺寸分公制（符号：DN）和英制（符号：NPS），国标阀门采用公制，美标阀门为英制。公制DN数值如下： 优先选用的DN数值如下： DN10 DN15 DN20 DN25 DN32 DN40...

Cut-off valve, throttle, valves, check valves and other valves are directional, if installed anti flip the throttle will affect the results of life; valve does not work, check or even dangerous. Generally valves, directional signs on the body; in case it does not, according to the valve works properly identified. Cut-off valve left-right asymmetry of the valve chamber, the fluid from the bottom to make it through the valve orifice, so fluid resistance (determined by the shape), open effort...

...

Technical support production and development of the valve, the valve is not a valve behind domestic than foreign, on the contrary a lot of products in the technology and innovation and international companies have been able to match. Development of the domestic valve industry is to end the modern direction of the front row. In the four forces of industrialization, urbanization, reforms and globalization, driven by China's valve manufacturing equipment or broad prospects, the future of...

...

Manual valve is a valve basic driving mode. It includes a hand wheel, lever or wrench two direct drive and driven through the transmission mechanism. When the valve start torque is large, it can be driven by a gear or worm gear, in order to achieve the purpose of omission. Gear sub spur gear and bevel gear drive. Gear reduction ratio, suitable for gate and globe valves, worm gear reducer relatively large for flash cocks, ball valves and butterfly valves

手动阀门是最基本的驱动方式的阀门。它包括用手轮、手柄或板手直接驱动和通过传动机构进行驱动两种。当阀门的启力矩较大时，可通过齿轮或蜗轮传动进行驱动，以达到省略的目的。齿轮传动分直齿圆柱齿轮传动和锥齿传动。齿轮传动减速比小，适用于闸阀和截止阀，蜗轮传动减速比较大，适用于旋塞闪、球阀和蝶阀

Pneumatic valves and hydraulic pressure based on a certain air, water or oil as a power source, an air cylinder (or cylinders) and the movement of the piston to drive the valve, general pneumatic air pressure is less than 0.8MPa, hydraulic pressure or low oil pressure is 2.5MPa ~ 25MPa. As for driving the diaphragm; rotary gas, liquid drive means for driving the ball, butterfly or plug. The driving force of hydraulic devices, suitable for driving large diameter valves. Such as for driving plug,...

(1) metal material valves: valve body and other parts made of metallic material. Such as cast iron valves, cast steel valves, valve steel, copper alloy valve, aluminum valve, lead alloy valves, titanium valves, Monel valve. (2) non-metallic materials valves: valve body and other parts are made of non-metallic materials. Such as plastic valves, ceramic valves, ceramic valves, glass steel valves. The following is some stainless steel valve material parameters and specific application (1)...