Basic Functions of a Weir Box

In a water management operation, there’s nothing more important than choosing your primary device. While there are a variety of excellent options, one tool that’s steadily growing in popularity is the weir box.

Essentially, a weir box is an artificial channel into which a weir plate has been installed. The weir box already contains the upstream pool that is necessary for a weir plate to function, making this one of the most effective flow management tools in the world. Learn more about the basic functions of the weir box and discover a few reasons you should install this versatile tool in your system.

Sizing Your Weir Box and Conditioning Flow

When installing a weir box in your system, there are a few issues that you will need to consider, including the proper size of your weir box and whether your flow will need to be conditioned.

When it comes to size, you need to make sure that your weir box is large enough that your operators can measure at the proper point. If the weir box is too small, it can cause your readings to be wildly inaccurate, impacting the success of your operation.

If the flow in your system is energetic, you should consider having your weir box equipped with a flow conditioning tool like an underflow baffle. This flow conditioning tool can create a uniform velocity profile so that your measurements will be as accurate as possible.

How the Weir Plate is Mounted

As mentioned, the main purpose of a weir box is to serve as a mounting location for the weir plate. When a weir plate is installed in a weir box, it will be mounted to a bulkhead to make sure that it is firmly in place. The plate will be installed levelly from side-to-side, and perpendicular to the flow in the weir box. While many weir plates will be constructed using stainless steel, fiberglass is a preferable choice, as it is extremely durable.

Several different notch styles can be used for your weir plate, with common options including a v-notch, rectangle, or trapezoid. The size and shape of the notch in your weir plate will have a big impact on the overall size of your weir box.

Flow in Your Weir Box

A great characteristic of a weir box is that flow can enter in one of two ways. Depending on the needs of your operation, flow can enter your weir box through either a piped connection or free-spilling discharge. The inlet piping in your weir box can be vertical or horizontal depending on if it’s equipped with an underflow baffle or not.

When using free-spilling discharge, an underflow baffle will always be used to even out the velocity profile.

Install a Weir Box

Now that you know more about the basic functions and structure of a weir box, you should consider installing this tool in your system with the help of Tracom, FRP.

Tracom provides our clients with a huge selection of dependable flow management products, including weir boxes. Contact us today to learn more about our product catalogue and to get help choosing the right tools for your system.