Our company offers various of hand valve series,such as 4H,4R,SH,3R,R5. Our company offers various of hand valve series,such as 4H,4R,3R,R5.Our company offers various of hand valve series,such as 4H,4R,SH,3R,R5.The hand pulled valve belongs to manual chang-over element, spool began to change to change-over to change the direction of the air current when the valve is operated by hand,Please choose ...