Clean-Outs - A Useful Weir Accessory

From time to time every weir installation will need periodic maintenance; whether to inspect the weir crest or to clean debris out of the weir pool. A simple and handy accessory to help with this is a clean-out opening or coupling. In weir boxes and manufactured channels, a clean-out allows the weir pool to be completely drained, while in natural channels it allows the water to drop below the crest of the weir.

cleaning a weir pool with board over clean-out drain

When sizing a clean-out it is important to make it large enough to pass the anticipated debris or allow the weir pool to be drained in a reasonable amount of time.

weir pool clean-out in action

When positioning the clean-out simply make sure to position it towards the headwall / discharge bulkhead and low enough to drain most (if not all) of the weir pool. In industrial applications it may be necessary to direct the clean-out discharge into a drain or back into the process stream. Make sure to allow sufficient space to make whatever temporary connection is necessary.

clean-out on an Openchannelflow stainless steel v-notch weir box

For weir boxes in industrial applications, it may be possible to permanently plumb the discharge to a receiving drain. If that is so, then a valve should be installed inline so that the operator can accomplish the drain procedure without assistance.