If installed on a fire sprinkler system, all mechanical checks, such as alarm checks and backflow preventers, should be flow tested and inspected internally in accordance with NFPA13 and NFPA25.

• 如果安装在防火喷淋系统上，所有机械式止回阀，如警告止回阀和防回流阀，都应该根据美国国家消防协会NFPA13和NFPA25标准进行流量测试和内部检查。