译文：
止回阀作为管道系统顺流时开启，逆流时关闭的阀门，主要用 于防止介质倒流，防止泵及驱动电机反转以及容器内介质泄放；目前使用最普遍的 是阀瓣围绕阀体销轴旋转的旋启式止回阀和阀瓣沿着阀体垂直中心线移动的升降式 止回阀，但以上2种结构的阀门均存在关闭时介质倒流速度从{zd0}迅速降为零，致 使管道进水管一侧内压迅速升高，从而产生对管路系统有破坏作用的水锤现象，所 以一般止回阀生产口径为50～500 mm。为减小止回阀的水锤效应 ，扩大止回阀的使用范围，作者设计在原产品基础上，增设缓闭副阀，解决了管道 水锤升压问题。 1、旋启式止回阀结构改进 在原旋启式止回阀阀瓣上增设缓闭副阀。副阀安 装在主阀阀瓣下侧或两侧且用螺纹联接，介质正常流动阀门开启时，介质压力将副 阀打开，介质通过副阀小孔流入主阀出口端，使主阀进水口端卸压，主阀阀瓣开启 ，主阀前后压力趋于平衡；介质逆流时，主阀阀瓣在逆流介质作用下快速关闭，而 副阀阀体上部为缓冲缸，副阀阀盖旋入阀体上部其盖上有一小孔，副阀阀瓣与其活 塞杆空套有一定间隙，活塞与缓冲缸之间采用O型橡胶圈密封，活塞下部与阀瓣之 间为平面密封；当副阀阀瓣随主阀阀瓣关闭而关闭时，因副阀阀盖小孔的作用，介 质通过小孔逐渐流入副阀缓冲缸上腔体，一部分介质通过副阀阀瓣与活塞杆之间的 间隙倒流，故副阀活塞是缓慢关闭的。该结构主阀的关闭相当于快关阶段，副阀的 缓慢关闭相当于慢关阶段，依据泵站机组水力和机械过渡机理说明该结构设计能有 效地防止水锤升压。 2、升降式止回阀结构改进 升降式止回阀又名底阀，它可以保持停泵时抽吸所需水柱；该阀结构改进的特点是在主阀阀瓣与阀体支架间增设一缓闭副阀。 阀体与底网间增设一垫环，以增补阀瓣上升的高度；缓 冲活塞与缓冲缸采用橡胶密封，阀瓣轴与活塞刚性联接，缓冲缸与阀瓣轴之间间隙 较小。当介质顺流时，压力介质推开阀瓣进入主阀体腔，同时推动缓冲活塞上移； 当介质倒流时，由于缓冲缸内部开启时已充满介质，而缓冲缸与阀瓣轴之间间隙较 小，因此随缓冲缸内介质通过间隙逐渐排出，主阀阀瓣关闭起到缓冲作用，使管网 内水锤升压得以控制。

“ Relief valve closed structural design of ”是由提供的国际阀门新闻，译文仅供参考。另外，中国止回阀网还提供相关产品搜索：、、、、等。

原文：
As a downstream piping system when the valve opens, reflux valve, when closed, the main medium used to prevent backflow to prevent the pump and drive motor reversal, as well as a container medium discharge; currently the most commonly used is the valve flap around the body Swing Pin rotation flap valve and the valve body along the vertical axis to move lift check valve, but the above two kinds of structures exist in the valve closed, medium speed back quickly from the largest drop to zero, inlet side of the pipe resulted in the rapid pressure rise, resulting in damaging effects on the piping system of water hammer phenomenon, it is generally a diameter of valve production of 50 ~ 500 mm. To reduce the valve of the water hammer effect, expanding the use of check valve, the author of the original product design based on the additional relief valve closed, deputy to solve the problem step-up of pipeline water hammer. 1, Swing Check Valve structure improvement Swing Check Valve in the original aortic valve an additional relief valve closed deputy. Vice-valve installed in the main valve side or both sides of the flap valve and the screw connection, the normal flow of media, the valve is opened, the medium pressure valve is opened by the Deputy, the medium through the valve hole into the mainvalve, Vice export side, so that the main valve inlet end of relief, the main valve valve flap to open, the main valve before and after the pressure balance; medium counter-current, the main valve valve valve in the counterflow medium under the action of fast closed, and the deputy valve body upper part of the buffer tank, the Deputy valve valve cap screwed the upper part of his body covered with a small hole, the Deputy valve valve valve with the piston rod sets have a certain air gap between the piston and the buffer cylinder with rubber O-ring seal, the piston and the valve flap between the lower-dimensional seal; as Vice-valve With the main valve valve valve valve valve was closed, because of Vice-valve valve cover the role of holes, the medium gradually flows through the small hole on the Vice-valve cylinder cushion cavity, part of the media, through the Deputy valve valve flap and the gap between the piston rod reflux, it is slow, Vice valve piston closed. This structure is equivalent to quickly close the main valve off stage, the Vice-valve slowly off the equivalent of the slow closing phase, based on hydraulic and mechanical pumping unit shows that the structural design of the transition mechanism can effectively prevent water hammer boost. 2, lift-type check valve structure improvement Lift Check valves, also known as the end, it can maintain the required suction pump to stop the water column; the valve structure is characterized by improvements in the main valve between the valve flap and valve stent slow addition of a Vice-valve closed. Valve body and at the end of net addition of a cushion between the ring in addition to the increase in the height of valve flap; buffer piston and cylinder with cushioning rubber seal, valve flap shaft and piston-rigid connections, the buffer tank, a smaller gap between the valve flap shaft. When the medium downstream, the pressure medium open the valve flap into the main body cavity, while promoting the buffer piston upward; when the medium back, due to open within the buffer tank when filled with media, while the buffer tank with the valve flap shaft gap between the more small, so with the buffer medium cylinder is gradually passed through the gap, the main valve valve valve cushion, so that water hammer within the pipe network to control boost.