The solution came from Lee Products who provided high Lohm rate restrictors from their 250 series axial visco jet range. Visco jets contain many internal stages to provide a very small restriction to flow but still keep the internal passageway sizes large enough to resist blockage by contamination.
Lee Products helps increase water restriction at hydro-electric power plant
During a recent refurbishment of the Allt na Lairige hydro-electric power station near Inverary in Scotland, the hydraulic control system was upgraded from the original low pressure system to a modern high pressure one. In-house designed multi-orifice restrictors were being used in the hydraulic actuators which operate the main water inlet valves but, due to the increase in system pressure and the variation in temperature throughout the year which was affecting the viscosity of the oil, it was determined that the restrictors were not providing sufficient restriction.
