Buckling fracture of PVC ventilation duct by the in-line monitor sampling

Matsubara, Tatsuo; Endo, Yuji; Yamanaka, Toshihiro; Kuramoto, Takao; Daiten, Masaki; Sugitsue, Noritake

The hard vinyl chloride ventilation duct of the local ventilation equipment for used centrifuge decommissioning system had fractured despite the ventilation stopping. As a result of investigation of the causes, it was found that negative pressure in the isolated duct with the damper valve exceeded buckling limit because the air sampling of air-sniffer was not stopped. For experimental proof of this, we investigated of attained negative pressure, analyzed buckling stress and confirmed that hard vinyl chloride ventilation duct was fractured quickly by negative pressure buckling with the mock-up examination device.