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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…

The section of the weir that the water overflows is termed the notch or overflow section. If the notch plate is thin enough that the water springs clear of the downstream face, the weir is terms a sharp-crested or thin-plate weir.

Over the years, there are have been a number of developments to the thin-plate weir – expanding weirs beyond the V-notch and Rectangular styles commonly used. Each special weir type is an attempt to overcome very specific limitations of the thin-plate weirs in general.

The usual method of dissipating the energy of a weir's nappe is by a hydraulic jump downstream of the weir. In an earthen channel, if the is no provision for this dissipation of energy, there will be a tendency to sour the downstream channel. This scour and erosion of the channel…

The common sources of errors for weir installations can be broken down into four categories: Flow approaching a weir installation should be no more than 0.5 fps and the upstream channel (weir pool) should be straight and of uniform cross-section for 20 times the maximum…

Automatic Samplers (also called autosamplers or simply samplers) collect and store water samples for laboratory analysis without the need for operator intervention. When used in conjunction with a flume or weir, automatic samplers can collect samples that are truly representative…

While weirs can be useful in a measuring flow in surface water applications, there are distinct disadvantages to using them. For a weir to develop the necessary upstream velocity profile, the channel upstream of the weir must conform to certain specific requirements:

Galvanized steel is commonly used for flumes and (somewhat less so) weirs in irrigation and water rights applications. Galvanized steel is economical and can provide a good useful lifespan.

At its simplest, a weir box is a fabricated channel into which a weir plate has been installed.

Stilling wells are chambers isolated from, but still connected to, a main flow of water. In clean water applications, the connection or pipe between the flume or weir pool and the stiling well is typically 1/10th the diameter of stilling well. This is usually large enought to…

A Packaged Metering Manhole (PMM) is a factory-integrated fiberglass manhole that mounts a flume, weir, mag meter, or other primary device to allow a user to measure or sample flows from full or non-full pipes. The manhole tube can also be supplied with a range of accessories,…

A flow measuring weir is simply a structure over which water flows in such a way that volumetric flow rate can be calculated….it lets you know how much water is flowing. Many times a flow measuring weir is simply a thin plate across a flow stream, but weirs can also be broad,…