Implementing a weir box in your open channel flow is one of the best ways to get highly precise flow rate measurements, provided that the conditions are favorable to that kind of hydraulic solution. If you want to keep getting accurate measurements, however, you’ll need to make sure that you’re keeping your weir clean and ready to go. Learn why you need weir maintenance, and discover what can cause common problems for weirs.
Upstream Problems
Upstream of any weir, you’ll find the weir pool, an essential aspect of a weir’s functionality. Keeping this pool clean is essential for proper functionality, though you should maintain the entire upstream channel in general. Common contaminants of the upstream channel include trash, sediment, and weeds.
When you’re maintaining the upstream conditions, it’s helpful to trim any vegetation around the channel and weir pool. Failing to do so could increase the chances of debris falling into the channel. After all, debris altering the elevation of the water in the weir pool can render your measurement efforts useless.
Weir Integrity
Even a good weir won’t be able to accomplish much if it’s not installed correctly. Be sure to inspect it routinely for any leaks. If you spot some, they need to be patched as soon as possible. Otherwise, water could bypass the weir entirely. This is especially important upon installation as a missed leak could render the whole effort pointless.
When installing a weir, it’s important to ensure that it’s both plumb and level. If there are any irregularities in either direction, you could be facing a situation in which your flow is bypassing the weir. This is especially important in environments that have frost heave. You may need to modify the foundation itself to keep the weir in place in the face of frost heave.
Weir Crest
The weir crest is absolutely essential for the functioning of a weir. You’ll need to keep it maintained or your weir is going to degrade fast. It must be level, free from damage and wear, and sharp, though not razor sharp. Rounding can be a serious problem that affects the aeration of the nappe, so maintaining that sharpness is especially important.
Don’t be surprised if you have to perform maintenance on the weir crest quite often. It’s common for items like fibrous materials and stringy particles to get stuck on the crest. You’ll have to clear these off whenever you can to keep the measurements accurate. Keep in mind that minor imperfections generally aren’t a problem, and fixing them can actually cause more problems. You only need to address issues that affect the normal surfaces and positioning of the weir.
Weir Boxes From Tracom
Now that you know why you need weir maintenance, you’re ready to make the most out of your weir. At Tracom, we have a wide selection of weir boxes available along with a team that will work with you to customize your weir to fit your unique flow channel conditions. Contact us today to get started!
