Warning: file_put_contents(): Only 0 of 5491 bytes written, possibly out of free disk space in /home/www/wwwroot/zidian/totle.com.cn/index.php on line 55 backflow connection是什么意思，backflow connection的翻译，backflow connection音标、读音、用法和例句_乐豆毛深蓝词典
Watts Dual Check Backflow Preventers can be specified in many different combinations of connection types, sizes, and union options. 美国瓦茨双止回防回流阀可以按照连接类型、通径和接头构成许多不同的组合。