FLECK 3900系列是双活塞工业用控制阀，比较适合用于双罐式大型系统，配成一用一备或同时运行、交替再生。可配合最大直径为1600mm的软化罐，连续出水量（压降0.1Mpa）为56.81m³/h。外接管径一般为3″。

3900技术参数：

阀体材料                                                        无铅黄铜
进/出口管径                                                    3″

流量范围（0.35Mpa进水压力）                         顶装                     侧装
连续出水量（压降0.1Mpa）                              56.81m³/h          56.81m³/h
峰值出水量（压降0.175Mpa）                          73.86m³/h          73.86m³/h
阻力系数 Cv                                                       65                       65
反洗流量（压降0.175Mpa）                             100gpm              100gpm

再生：
顺流/逆流                                                        任选一项
程序调节                                                         所有再生步骤时间均可调节
最大再生时间                                                   164分钟

流量计精度 2″                                                0.68-34.09m³/h±5%
                3″                                                1.59-68.18m³/h±5%
流量计量程 2″                                                标准  4.73-80.49m³
                                                                     加大  23.67-402.46m³
                3″                                                标准  14.2-241.47m³
                                                                     加大  71.02-1207.38m³
无硬水旁通                                                      是

主要尺寸：
中心管直径                                                       3″
排水管直径                                                       2″（female）
盐液管直径                                                       3/4″（male）
罐体接口直径                                                    6″-8UN或法兰接口
阀体高度（由阀体顶端至罐体接口）                      15″