(EN) The invention relates to a stop valve (100) comprising a magnetic yoke (101), a solenoid coil (102), a compression spring (107) and an armature (105) on which an elastic membrane (106) is arranged. The membrane (106) can be sealingly pressed onto at least one fluid connection (108, 109). The stop valve (100) further comprises a guide (111) and a guide pin (110) that is connected to the armature (105). Finally, the compression spring (107) is positioned in such a way as to surround the solenoid coil (102). Also disclosed is a method for detecting leaks and/or identifying variations in metered amounts. Said method, which is carried on in an SCR system comprising the stop valve (100), involves opening the stop valve (100), whereupon a pressurized line is filled with a reducing agent and the stop valve (100) is closed. A pressure is subsequently lowered upstream of the stop valve (100) by shutting off a pump. Finally, any leak is detected and/or variations in the metered amount are identified by having the pressure sensor monitor the pressure downstream of the stop valve (100).
(ZH) 本发明涉及一种截止阀（100），所述截止阀包括磁轭（101）、电磁线圈（102）和压力弹簧（107）以及磁电枢（105），在所述磁电枢上布置了有弹性的膜片（106）。在此，所述膜片（106）能够密闭地压紧在至少一个流体接头（108、109）上。此外，所述截止阀（100）包括导引机构（111）和导向销（110），所述导向销与所述磁电枢（105）相连接。最后，所述压力弹簧（107）如此布置，使得其包围着所述电磁线圈（102）。本发明涉及一种用于进行泄漏探测和/或配给量偏差识别的方法，所述方法在包括所述截止阀（100）的SCR系统中执行，所述方法包括所述截止阀（100）的打开。随后用还原剂来填充压力管路并且将所述截止阀（100）关闭。接着，通过泵的切断来降低所述截止阀（100）上游的压力。最后，借助于所述压力传感器通过对于所述截止阀（100）下游的压力的监控来实施泄漏探测和/或配给量偏差识别。
