Piped Internal Bypass

Please refer to the product overview for details of operation. The maximum flows shown are usually the 10-year or 25-year flows taken from the pipe system design chart. Water Quality flows are typically 20 to 30% of this flow. Our designs analyze and can accept the largest expected storm flows, but center their efficiency around the water quality storms. Your local regulations may allow slightly higher than maximum flows, or may require slightly lower flow limits. The chart under "Technical Specs" is to get you started. Please visit our Links & Downloads section to get a CrystalStream Design Sheet or complete our Online Design Form to get a design specific to your area.

  • Model Number: i.e. Model 2466-IB

Piped Internal Bypass vault systems are based on twin vault systems, but are limited to parallel vault arrangements. The bypass vault system adds a “relief” or bypass pipe located above the normal connector pipe and outlet pipe, so that additional flows can be accommodated. These systems are used when flows from off site add to the total flow volume of a design, but not to the water quality flow.  We also manufacture Intergral Internal Bypass Systems which feature our “periscope” type bypass.  This type of bypass is also used in the CrystalCombo Hybrid Polisher Systems.

In bypass vault systems, the trash screening basket and two out of three baffles are in the front vault. All flows, including bypass, pass through the trash screening basket. A third baffle, the spill protection reservoir,and the coconut fiber filter are in the second vault. Normal flows enter the device from the endwall, top, or one side wall of the front vault, pass through the treatment elements in that vault, and then cross over to the second vault via a connector pipe. Normal flows then pass through the remaining elements in the second vault, and exit out the back of that vault through the endwall, or either side wall. When flows reach a predetermined design level, the device will begin to bypass. Most of the flow will still pass through all treatment elements, but some flow will pass through the trash screening basket, through both vaults that act as sediment traps, and out of the device. The position of the bypass pipe (above the connector pipe) assures that the full treatment flow will always be higher than the bypass flow. For these systems, two vaults must be parallel as shown in the sketch above. There are other possibilities when special circumstances dictate, but they are not as cost efficient. The capacities of our twin vault bypass devices are shown below. The capacities will change, based on the position of the bypass pipe, and the hydraulic gradient in your pipe system. In some areas, other sizes may be available.

Model Vault Dimensions (H x W x L) Total Flow Path Maximum Flow
1246 IB 6' x 4' x 6' 12' 17 cfs
1856 IB 9' x 5' x 6' 18' 32 cfs
2056 IB 10' x 5' x 6' 20' 35 cfs
2466 IB 12' x 6' x 6' 24' 50 cfs