Type : Over & Under Pressure
Set Pressure : Air Out : 5 ~ 50 mm Bar. Air In : 2.5 ~ 50 mm Bar
Size : 2” ~ 10”
Connection : Flange PN, ANSI
Body : Ductile Iron, Stainless Steel
Trims : Stainless Steel
Protection : IEC : Group I, IIA, IIB3. NEC : Methane, D,C
Compliance : 94/9/EC, ATEX 95, ISO 16852
BS&B manufactures wide range of Breather Valves to protect Tank & other Equipment. BS&B 937E series is for both Air In & Air Out application
http://www.bsbsystems.com/Flame_Arrester/Vacuum_Relief_Vents/Model937E.html