There are seven 96-inch hollow jet valves located at Friant Dam; four at the San Joaquin river outlet, two at the Friant-Kern canal outlet and one at the Madera canal outlet. The valves are an important component in the ability to make water deliveries and regulate flood control operations, and so, must be in good and dependable operating condition. Due to several factors, including lubricant deterioration, scale build-up, rust, and water intrusion, the valves are overhauled on a four-year rotating basis. This project included:
- Removing the existing 96-inch diameter hollow-jet valve, associated motor operator, adapter, and appurtenant parts and relocating them to a storage location on site
- Cleaning exposed outlet pipe flange
- Furnishing, installing and testing one motor-operated 60-inch fixed-cone valve. Transition, and backwater bulkhead adapter plate
BCI removed, transported, and stored the existing jet valve by disconnecting the drive unit and removing lifting bay covers, unbolting and disconnecting the valve, and positioning the valve upright for disassembly. Then the valve components were removed leaving only the valve body to be hoisted and secured to a trailer. The valve was unloaded at BOR storage and then the components reassembled. BCI used the existing government overhead gantry crane for the installation of the new valve. The fixed cone valve was installed as four separate components: the valve/hood spool assembly, transition spool, hood, and dismantling flange. Once the installation was complete and all bolts were torqued, touchup paint was applied, floor grating and backwater bulkhead reinstalled, and the backwater bulkhead adapter plate installed along with a new gasket.