air vent valve 1.> material:brass 2.> size: 1/2",3 ... 8" 3.> working temperature: < 100 degree 4.>working pressure:3 bar Avonflow Baiyilun TRV Co.,Ltd.specialized in the manufacture of ... Croatia,Turkey, Poland, Ukraine, England, New Zealand and so on. air vent valve:1. material:brass2. size: 1/2",3/4 ... ",3/8"3. manual air vent4.working pressure:3 bar5.working temperature: < 100 degree ...