User Manual Series F-BO-AFE70 Chapter 8 • Mounting and connection of pneumatic components8.2.3 Use of check valvesIt is recommended that a check valve should be mounted at the end of every branch of the pipe sys-tem. Mounting a check valve ensures that the dirt particles and ice particles will be blown out ofthe pipe in the best possible way. In addition, the check valve also serves to limit the pressure in thepiping, thereby relieving the aspiration holes during the Purging process. Ideally, the opening over-pressure of the check valve should be around 25kPa (0.25bar).The cleaning of the aspiration holes is also ensured without a check valve, but it is not ensuredthat the dirt particles will be blown out along the whole length of the pipe in the best possibleway.8.2.4 Connection diagram for a double pipe systemThe following figure shows the schematic connection of the components needed for purging twoseparate pipe systems of an aspirating smoke detector.Fig. 8: Aspirating smoke detector with two separate pipe systems. As a supplement to Fig. 2 (page 10),electrical connection cables are not shown here in order to provide a clearer overview.A … Aspirating smoke detector with two separate pipe systemsB … F-BO-AFE70 for the first pipe systemC … Filter before the Purging unit of pipe system 1 (option)D … F-BO-AFE70 for the second pipe systemE … Filter before the Purging unit of pipe system 2 (option)If the aspirating smoke detector used has separate fault outputs for each individual pipe network,the Purging units can be actuated individually. As a result, the pipes can also be purged independ-ently of each other in the event of a fault.If the aspirating smoke detector used does not have separate fault outputs for each individual pipenetwork, but has only one common fault output for all pipe networks, the Purging units must beconnected and operated in the master-slave mode. In this case, the pipes will always be purgedtogether.I56-4252-010D200-104-0027