For a flume to operate correctly the flow approaching it must be sub-critical and under open channel (non-full pipe) flow conditions.  Sometimes, however, the space available at a site means that where the flume has to be situated clashes with the ability to properly condition the flow before it enters the flume.  For these applications, Openchannelflow has developed Energy Absorbing Manholes. 

Energy Absorbing Manholes allows an operator to bring in full pipe or energetic supercritical flow, dampen the flow, and then direct it out in a controlled manner.  The resulting flow is sub-critical and much of the turbulence has been eliminated. 

Energy Absorbing Manholes work equally well on flows entering / exiting the manhole on the same elevation as well as those where the flow drops into the manhole (leaving at a lower elevation).

Most Energy Absorbing Manhole configurations work well is sanitary or solids laden flows – passing these solids with minimal collection in the Energy Absorbing Manhole. 

When used in conjunction with Packaged Metering flume or weir manholes, Energy Absorbing Manholes can greatly reduce the amount of upstream conditioning (and space) necessary for accurate flow measurement.