Fire Protection System Installations: The National Fire Protection Agency (NFPA) Guidelines require a confirming flow test be conducted by a certified tester whenever a main linevalve is installed, such as a shut-off valve or a backflow preventer.
Fire Protection System Installations: The National Fire Protection Agency (NFPA) Guidelines require a confirming flow test be conducted by a certified tester whenever a main linevalve is installed, such as a shut-off valve or a backflow preventer.
消防系统安装：美国全国消防局（NFPA）指导方针要求在安装“主管道”阀门时要由有资格证书的检验员对关闭阀或防回流阀进行流量检测。