Air Valve

Air Valve, Single Chamber, Double Orifice, Triple Function
Product Description:
In this type of valves aeration and air evacuation are carried out automatically in primary and secondary pipelines in sewage networks. These valves are light in weight due to their internal parts being made of plastic and their unique
design and this allows installation in lower altitudes. I have this text from product catalogue.
Product Features:
Triple function: air release during the filling of the pipe system, air release under full operation and full working pressure, venting of air for vacuum breaking purposes.
Automatic air venting of the fluid in the main pipe and supply lines. In these type of valves the fluid flow activates the venting operation. Large venting orifice allows large volumes of air to be released on start-up and enter the pipe for vacuum breaking on shut down. Small venting orifice allows volumes of air to be released under the fluid pressure. Unique feature and internal components of plastic materials result in low weight, allowing easy assembly on lines.
Applications:
This type of valve could be used with sewage mediums at minimum pressure of 0.3 bars to a maximum temperature of 70° C.
Technical Details:
Flanges : DIN-EN-1092-2 (DIN-2501)
Body : EN-GJS-400-15[DIN-EN-1563(DIN-1693)]
Bonnet : EN-GJS-400-15[DIN-EN-1563(DIN-1693)]
Floater : AISI 304 (1.4301)
Stopper : POM
Seat : POM
Guide Rod : AISI 304 (1.4301)
Guide Screw : AISI 304 (1.4301)
Sealing Rubber : NBR / EPDM
Bolts and Nuts : A2 (DIN-912) Medium : potable water, raw water
Temperature : up to 70 °C
Size (mm) : 50 – 200
Pressure (bar) : 6 – 16
Corrosion  Protection : All internal components are made of plastic (HDPE 100) and are protected against corrosion. All casting parts are coated with epoxy powder RAL 5005 by electrostatic method.