Alden was contracted by Imperia Engineering for mock-up and head loss testing of cured in place pipe (CIPP) lining. Seabrook Nuclear Power plant was planning to perform maintenance on its service water piping system which consists of safety and non-safety function concrete lined pipe. The planned maintenance consisted of lining the pipes using a glass fiber reinforced epoxy resin composite. To ensure the maintenance activity would be successful, Imperia Engineering organized a mock-up test of the installation mechanics for the smallest inner diameter pipe (20”) and contracted Alden to perform flow testing on the mock-up pipe loop to help determine the effects of the lining on the flow performance of the piping network.
The chosen piping configuration for the mock-up test focuses on a section of 20” pipe that supplies systems related to turbine cooling. The section in question combined a number of direction and elevation changing pipe fittings. Incorporating this section into the mock-up provided a challenge for the installer and provided some insight into the potential stack-up of flow losses from these types of fitting combinations. It made the positive identification of individual fitting losses much more challenging.
Along with assembling the provided test piping, Alden constructed a custom flow loop with a large recirculation pump and a flow meter assembly. The flow meter assembly consisted of two flow meters allowing measurements of flow rate to better than 1% uncertainty down to 2000 gpm. The recirculation pump had a relatively low discharge head capability (<45ft) but a high run out flow rate of 17,500 gpm. The loop was connected to a large water tank reservoir to allow the loop to be reconfigured and accessed between tests.
Each piece of test piping was outfitted with multiple sets of taps for the purpose of pressure loss measurements. Pressure loss measurements along the pipeline were taken at a range of flow rates to evaluate Reynolds number effects.
The pipeline was tested by Alden first in its original cement lined state, then with Weko seals installed at various joint locations, and then finally following CIPP lining of the entire length of test piping (lining performed onsite at Alden by Aquarehab). Alden analyzed the test results to determine friction losses and loss coefficients for each type of fitting and straight sections of pipe, under all three scenarios, providing the required insight to the viability of CIPP lining at Seabrook. Measurements showed that the friction factor drop in the pipe was sufficient to compensate for the reduced pipe diameter. However, losses substantially increased at turns where excess material folds increase turbulent losses by obstructing flow near the inside turn of the wall. Mock-up testing and careful hydraulic analysis is therefore required when applying the lining system to a pipeline where the pump performance margin is small.
Contact us for more information on mock-up testing.
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