Fiberglass Metering Manhole vs. Precast Concrete By admin | | Comments Off on Fiberglass Metering Manhole vs. Precast Concrete For more information contact a CC Lynch representative or callĀ us at 1-800-333-2252. Posted in Flow Measurement, flow metering and tagged Corrosion, FRP Gates, Metering Manholes, plasti-fab, Precast Concrete