译文：
当减压阀的输出压力较高或通径较大时，用调压弹簧直接调压，则弹簧刚度必然过大，流量变化时，输出压力波动较大，阀的结构尺寸也将增大。为了克服这些缺点，可采用先导式减压阀。先导式减压阀的工作原理与直动式的基本相同。先导式减压阀所用的调压气体，是由小型的直动式减压阀供给的。若把小型直动式减压阀装在阀体内部，则称为内部先导式减压阀；若将小型直动式减压阀装在主阀体外部，则称为外部先导式减压阀。 图14—2所示为内部先导式减压阀的结构图，与直动式减压阀相比，该阀增加了由喷嘴4、挡板3、固定节流孔9及气室B所组成的喷嘴挡板放大环节。当喷嘴与挡板之间的距离发生微小变化时，就会使B室中的压力发生根明显的变化，从而引起膜片10有较大的位移，去控制阀芯6的上下移动，使进气阀口8开大或关小、提高了对阀芯控制的灵敏度，即提高了稳压精度。 外部先导式减压阀的主阀，其工作原理与直动式相同。在主阀体外部还有一个小型直动式减压阀，由它来控制主阀。此类阀适于通径在20mm以上，远距离(30m以内)、高处、危险处、调压困难的场合。

“Pilot-valve works ”是由提供的国际阀门新闻，译文仅供参考。另外，中国减压阀网还提供相关产品搜索：、、、、等。

原文：
When the valve's output pressure of a higher or larger diameter, with a direct pressure regulator pressure regulator spring, then spring stiffness must too large, flow rate changes, the output pressure fluctuations, the structure of valve size will increase. In order to overcome these shortcomings, pilot-type valve can be used. Pilot-valve works with the direct-acting type of basically the same. Pilot-operated pressure regulator valve used in gas is determined by a small supply of direct-acting pressure reducing valve. If the small-scale direct-acting pressure reducing valve installed in the valve house, then known as the internal pilot type valve; Ruoqiang a small direct-acting pressure reducing valve installed in the main valve outside, then known as the external pilot type valve . Figure 14-2 shows the structure of the internal pilot type valve diagram, as compared with the direct-acting pressure reducing valve, the valve increased from nozzle 4, baffle 3, the fixed throttle hole 9 and the gas chamber formed by B baffle larger part of the nozzle. When the distance between the nozzle and baffle small changes occur, they will make B, the pressure in place significant changes in the root, causing diaphragm 10 has a larger displacement, to control the spool 6 moves up and down, so that entry valve port to open eight large or off small, increase the sensitivity of the spool control, namely, increased regulation accuracy. External pilot type valve of the main valve that works the same as with the direct-acting type. Outside the main body there is a small direct-acting pressure reducing valve, which it has to control the main valve. Such valve is suitable for 20mm or more in diameter, distance (30m or less), height, danger Department, the regulator difficult occasions.