Hollow jet valves
The Hollow jets (HJ) – original operational gate for lower discharges of dam reservoirs is at present the most reliable control gate with very good control properties, high flow coefficient and very good tightness, which provides for effective aeration of the outflow jet and absorption of its kinetic energy – creation of the “hydraulic jump” – in case of correct design of the discharge chamber of square section (chamber of shape XIII), or a cylindrical chamber with conical insert. Other of its advantages to other types of control gates include its simple design with minimum operation and maintenance requirements.
medium: river water
- Nominal inside diameter: do DN 2000
- Nominal pressure: do PN 40
- via gear box and electric drive
- via hydraulic servo-cylinder
RU can be controlled on-site or remotely (from a control room). In the closed as well as open position, the control is switched off by position limit switches, whose function is secured by torque switches. The intermediate position can be selected according to the required flow within the range of 10 to 100 % of stroke (at underwater outflow,owing to the aeration problematic, within the range of 15 to 100 % of stroke).