快开阀门上最好自带一个自动回位弹簧，松手即刻关闭。

The quick-opening valve is better provided with an automatic return spring so as to close the valve after being released.

youdao

快开阀门上最好自带一个自动回位弹簧，松手即刻关闭。

The quick-opening valve is better provided with an automatic return spring so as to close the valve after being released.

youdao