threaded connection的用法和样例：
例句
- Threaded end connection checks shall have an iron body and solder end connection checks shall have a bronze body.
螺纹连接端口的止回阀应该是铸铁阀体，焊接连接端口的止回阀则应该是青铜阀体。 - Threaded connections may only be used if allowed for by piping specifications, otherwise these shall be flanged.
螺纹连接只可在配管规范的允许下使用，不然应是法兰式的。
