代号

What's the code for Tianjin?

天津的是多少?

Hand wheel,lever and spanner driving and safety valve,pressure reducing valve,traps overleap this symbol.

1、手轮、手柄和扳手传动以及安全阀、减压阀、疏水阀省略本。

The content of basic standard has: Method of code name of substantival term, symbol, mark, standard weaves the method.

础标准的内有：名词术语、、标记方法、标准编排方法等。