SIAV & VTB Series are the only dry positive displacement blowers capable of attaining 28" Hg (93% vacuum). Our vacuum blowers SIAVVTB are also available in Atex category 2 version, on request (Atex II 2 GD c IIB T3 160C) Applications S.I.A.V. series blowers are engineered primarily for vacuum applications. They can alternatively be used for pressure unloading.Standard applications are:Vacuum trucks (industrial, septic, municipal, etc.);Fly ash vacuum pneumatic conveyingEvaporation, Centralized plant vacuumSoil remediation