ACU-JET (Jet Regulator)

The ACU-JET Jet Regulator System is designed to maintain a constant and accurate flow (+/- 5%) from a minimum of 235 gpm (15 L/s) to a maximum of 32 000 gpm (2 000 L/s) for upstream water levels varying from 0 to 40 feet (12 m). The ACU-JET Jet Regulator has been used for flow control in combined sewer systems (CSO), sanitary sewer systems (SSO) and effluent from batch process plants and is well suited to regulate medium to very large discharges. The ACU-JET Jet Regulator is installed on the downstream side of the control point in a dry well and requires no differential head for proper operation.


  • 235 gpm to 32 000 gpm (15 to 2 000 L/S)
  • Headwater up to 40 feet (12 m)
  • No floor offset required
  • May be equipped for remote operation
  • Automatic self-flushing effect prevents blockage
  • Design discharge can be adjusted on site
  • Easy to retrofit into existing installations
  • Stainless steel construction

Range of Application

The ACU-JET Jet Regulator System can vary from a model GAJ-R-20 to GAJ-R-100/60. The GAJ-R-20 has an inlet diameter of 8 inches (20 cm) with a flow range of 235 to 1 030 gpm (15 to 65 L/s) and the GAJ-R-100/60 has an inlet opening of 40 inches (100 cm) wide by 24 inches (60 cm) high with a flow range of 20 800 to 32 000 gpm (1 300 to 2 000 L/s). The ACU-JET’s model selection is based entirely on the flow range required.

System Operation

The ACU-JET Jet Regulator maintains a constant discharge at a set value independent of the upstream water level. The ACU-JET Jet Regulator is effectively balancing the force of the water flowing through it against the jet shield. The most important functional elements are the pivoted radial gate, the jet shield and the regulating counterweight. During low flow periods, the pivoted radial gate remains in the fully open position. As the influent discharge increases, it flows through the regulator housing and is directed against the jet shield. The increasing force of the water pushes the jet shield up against the force of the regulating counterweight. Both movements are transferred to the pivoted radial gate by means of coupled levers which initiate the regulating process. As the force of the water on the jet shield increases, the pivoted radial gate closes thereby decreasing the discharge opening. The ACU-JET Jet Regulator opening is automatically adjusted to match the upstream water level, resulting in a constant regulated discharge.


The ACU-JET Jet Regulator has an automatic self-flushing effect to prevent blockage. If a blockage occurs, then the flow through the regulator decreases, resulting in a corresponding decrease of the regulating force of the water on the jet shield. This causes the jet shield to drop and the radial gate to open fully. This flushes the blockage out under the pressure of the upstream water level after which the regulating process resumes.


Each ACU-JET Jet Regulator is calibrated on a fully functional, full scale test stand. Each ACU-JET Jet Regulator is shipped to site pre-set to the desired design flow. In addition, set points are clearly indicated for future in-situ flow adjustments (should it be required). The regulator can then be installed and put into operation without requiring time consuming and cost intensive in-situ flow calibration or measurement.


The ACU-JET Jet Regulator can be equipped with a servo-control unit to modify the design flow from fully open to closed. An ACU-JET Jet Regulator can be controlled using the local control or remotely from a central control location. In case of power outages, the regulator will continue to operate by automatically maintaining the constant discharge it was last set at.