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
7- Connection: Threaded or Flanged acc to. BS4504/DIN2532/ISO 7005
WALTER-FSV COMPANY Supply Flanged Double Orifice Air Release Valve, Combination Air Release Valve for water and sewage water. And Thread Air Vent Valve .
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