Trash baskets, Sediment Buckets, Screens & Strainers
Trash baskets and sediment buckets are extremely useful components of a drainage system. They create a point where debris and sediment can be collected. This keeps foreign material from entering the piping system. While the selection of a trash basket or sediment bucket is often overlooked, it is a vital decision that will affect drainage performance, maintenance, and overall life cycle costs of the drainage system.
What is the difference in a "Trash Basket", "Sediment Bucket", "Screen", and "Strainer"?
Many people and even other drainage companies use all of these terms somewhat interchangeably. This often starts because they only offer limited options. Dura Trench believes that this is a big mistake. We know these are different to engineers who know. Here is the difference...
A trash basket is meant to capture floating trash and debris. This material is typically strained off in a basket with holes. The "basket" feature means it can be easily lifted and dumped.
A sediment bucket is a solid bucket allowing heavy fines to fall into the bucket and settle to the bottom. This too can be lifted and dumped. A sediment bucket typically goes below the outlet pipe acting as a holding tank giving time for sediment to fall out of the liquid stream. A trash basket typically goes above the outlet pipe and screens all liquid through the perforations in the basket.
A screen is a mesh plate inserted into the flow line of a trench or inside a basin. It screens debris into the compartment created upstream of the screen. These can be spaced along the flow line to provide graduated and reducing mesh sizes. This can be helpful in screening particulate without completely plugging or blinding small holes as rapidly. This option does not typically offer any way to remove the debris.
A strainer is a perforated screen that is placed over the outlet pipe. It is just as it sounds, a straining device that fits over the pipe itself straining out debris. It acts similar to a trash basket but leaves the debris sitting in the bottom of the trench or basin. This option has a lower cost but offers no way to remove the debris that is left in the bottom of the drain.
Selecting between a Trash Basket or Sediment Bucket
The first thing that should be considered is what are you trying to capture....debris or sediment? If you are capturing debris that is floating you will want a trash basket. These capture everything from grass clippings to bottle tops to animal hair. The smaller the object being collected the smaller the holes will need to be. There should be a balance though. Smaller holes tend to plug and blind. Smaller holes will need more frequent cleaning. The holes should be as large as possible while still protecting the piping system from excess debris and clogging. DuraTrench offers two standard size holes - 1/4" and 1/8". It is important to note that we have provided many other size holes upon request. We have provided holes as large as 1" and down to mesh sizes for things like DE (diatomaceous earth).
A trash basket typically has the piping located such that all of the liquid must pass through the basket before entering the pipe. This ensures that all liquid is screened through the basket.
If sediment is being collected a Sediment bucket is in order. These are solid buckets that sit on the bottom of the basin. This material is typically a suspended solid that will fall to the bottom as the flow slows or over time. This can be dirt from a parking lot to stone dust in a counter top manufacturing facility. Because these buckets are solid the pipe is placed above the basket. The volume below acts to create laminar flow which settles out the suspended solids. It is best to place the outlet pipe across from the inlet versus on the side. This gives maximum time in the laminar area to remove a maximum volume of solids. The longer the laminar flow section the more likely the solids are to fall out into the bucket. Note that a longer basin with multiple buckets may be required to properly remove the sediment.
Wet material can be very heavy. Be sure to think about how to lift the basket or bucket. Large size baskets may need to be lifted with a piece of equipment. A good rule of thumb is that a cubic foot of wet material may weigh upwards of 150 lbs per cubic foot.
Proper design of a trash basket
Non corrosive material
Size vs weight
Duration between cleaning - how to determine