Small size air vent valve is screw type, normally is will be install with a thread ball valve . We also have Double Air Release Valve of Flange type. There is a large and a small orifices. The large one can intake and release large amount of air. The air way of the large orifice is sym-metrical which makes the air releasing amount more than that of the same size double orifices air releasing valve
Suzhou Walter-fsv Company always keep eyes on products quality. WALTER-FSV Supply OEM Service for air vent valves. And also include all kinds of valve.
){kind=link}