How to Install a Weir Channel
A successful Weir Channel installation requires that the weir be set correctly and the channel secured.
Installing the WEIR CHANNEL
The Weir Channel should be set so that it is centered in the flow stream.
The mounting surface of the weir box should be sufficiently consolidated that it will not shift or move out of position due to settlement, frost heave, etc.
The floor of the Weir Channel should be set high enough so that the weir does not operate under submerged flow conditions.
The Weir Channel must be level from front-to-back and from side-to-side (using a level on the floor - not the top - of the Weir Channel).
The weir crest must be horizontally level.
If present, the bevel of the weir crest must be set downstream.
In earthen channel applications, the channel downstream of the Weir Box should be reinforced / armored so that scour does not occur. Scouring can lead to the Weir Box shifting out of position.
Water Measurement with Flumes and Weirs (ISBN 90-70754-55-X) provides details of channel reinforcement, however as a rule of thumb protection should extend at least 4 Hmax downstream (and not less than 5-feet [1.5 m].
The Weir Channel must be braced internally (plywood and lumber are typically used) during installation to ensure that distortion does not occur.
The Weir Channel must not float out of its intended final position during installation.
Bracing
The bracing at the top of the Weir Channel should be left on until the installation is finished.
If the Weir Channel is set in concrete, the bracing may be removed once the installation is finished.
For installations where the Weir Channel is free-standing or otherwise not set in concrete, the bracing should be left in place. If the bracing is removed, verify the dimensional accuracy of the Weir Channel after the removal.
Joints
Weir Channels supplied with wing walls must remain sealed between the joints. While these joints may be sealed initially at the factory, a final visual inspection of all joints should be done before installation. Where required, apply one or two continuous beads of silicone on all seating surfaces before proceeding with the installation.