富莱克3900控制阀属于双活塞工业用控制阀系列，主要由2900、2930、3900型控制阀组成，适用于双罐系统，而无需外加阀门控制。  
结构特点：活塞为横向布置，有两只活塞，一只控制再生程序，另一只实现进出水切换，阀体材质均为无铅黄铜，可选配无硬水旁通活塞。配成双罐系统或多罐系统，无需外加阀门即可实现。适用于锅炉用软水器，及其他工业用软水器。
        
富莱克FLECK3900控制阀特点与说明
3900详细说明：      
        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技术特性：
阀体材料                                                                                                                无铅黄铜
进/出口管径                                                                                                                  3″
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″