HOBAS Pressure Release Shaft

HOBAS Pressure Release Shafts are used for the transition of pressure pipelines into gravity pipelines. The outlet to the gravity pipeline is designed below the crown of the incoming pressure pipe. Pressure Release Shafts have the same properties as HOBAS Standard Shafts.


  • Pipe shaft
  • Anti-buoyancy slab
  • Flanged inlet socket
  • Outlet
  • Laminated pipe shaft coupling (on multi-unit designs)
  • Ladder
  • Manhole cover