How It Works - ER Series
The ER-200 Series BFD's can be configured in three different ways. Each configuration provides different advantages in flow characteristics, tailwater interaction, and cost.
|A single restriction ER Series BFD restricts flow though the interstitial opening only. There is no flow through the inner tube The inner tube functions as a vent. This device is most cost effective when tailwater is not a consideration.|
|A hybrid ER Series BFD restricts flow through both an inner orifice and through a fixed interstitial opening. The fixed interstitial opening is located at the rim of the stationary riser. Therefore, the hybrid ER Series BFD can not produce a constant flow rate, however this configuration does provide a hydraulic advantage over a traditional weir or orifice. The hybrid ER Series BFD can prove useful in high tailwater applications.|
|A dual restriction ER Series BFD restricts flow through both an inner orifice and through a moving interstitial opening. The moving interstitial opening provides a constant flow rate like the single restriction configuration, with the tailwater charecteristics of the hybrid configuration. The dual restriction ER Series BFD is most effective when constant flow rate is required in a high tailwater application. Click here to see typical rating curves.|