双向止回阀 meaning in Chinese

double non-return valve
dual way check valve

Dual way check valve
双向止回阀双通单向阀
So the pressure signal of control air holds the single - acting cylinder at the stop position through the pipe named “ supply ” , the 3 - way valve ( pos . no . 22 , upper frame ) , the double check valve ( pos . no . 72 - 1 ) and the quick release valve ( pos . no . 41 , right frame )
因此控制空气的压力信号保持单作用气缸在停止位置通过管路supply ，三通阀22 ，上位，双向止回阀72 - 1和快速泄放阀41 ，右位。