箭头位置指示器组件
Arrow Position Indicator Kit

　　美国斯毕尔公司旋启式止回阀指示器组件设计用于在美国斯毕尔公司旋启式止回阀上现场安装外置指示器箭头。这种组件通过阀盖总成进行安装，不需要从管道上移动阀门。
　　Spears® Swing Check Valve Indicator Kit is designed for field installation of external Indicator Arrow in Spears® Swing Check Valves. This kit can be installed through the bonnet assembly and removal of valve from line is not required.

组件包括：
Kit Includes:

平衡锤应用
Application of Counter Balance

　　当流体流动打开旋启式阀瓣时，旋启式阀瓣处于工作状态。当流体流速减慢并且逆向流动时，阀瓣反应旋启到关闭位置。流向突然逆向可能在阀瓣关闭时产生“拍击”现象。平衡锤机制的功能就在于当流体流速开始减慢，阀瓣就提前开始关闭，这样当流体逆向一旦发生，阀瓣几乎能够即可关闭，因此也避免了阀瓣的拍击。可安装在阀门上作为阀门的整体装置一起提供，也可以以组件形式作为已安装阀门的改装部件。
　　Swing Check Valves operate in response to a fluid stream flow opening a swinging disc. As the fluid stream slows and reverses, the disc responds by swinging to the closed position. Sudden reversal of flow direction can result in "slamming" condition as the disc closes. The function of the Counter Balance mechanism is to start the disc closing earlier as the fluid stream begins to slow so that it is almost closed when flow reversal takes place, thereby eliminating slamming of the disc. Available as installed unit with valve or as a kit for adaptation of installed valves.

平衡锤组件
Counter Balance Kits

　　美国斯毕尔公司旋启式止回阀组件设计用于美国斯毕尔公司旋启式止回阀平衡锤机制的现场安装。这种组件可以通过阀盖总成进行安装，不需要将阀门从管道上拆卸下来。
　　Spears® Swing Check Valve Counter Balance Kit is designed for field installation of counter balance mechanism in Spears® Swing Check Valves. This kit can be installed through the bonnet assembly and removal of valve from line not required.

组件包括：
Kit Includes: