Service exchange (SDI) or portable exchange (PEDI) DI tank users may have a better option. SDI and PEDI systems allow for the use of a service provider’s DI tanks for the purpose of high purity water production. These tanks are used across a wide variety of industries for humidifier feed, washing/rinsing, lab water, aquatics/reefkeeping, chemical formulation, research, science and analytical applications, just to name a few. For these users, water quality is critical to their process. For some deionized water users, exchange tanks are the most practical vehicle for water production. For others, it is perceived as their only option.
Enter DI cartridge systems. DI cartridges contain the same cation and anion resin that is utilized in mixed bed tanks, only in a smaller package, with less capacity and lower flow rate capabilities. Systems are configurable based on the application and are easily expandable in the future.
With exchange tanks:
- Tanks are commonly exchanged with capacity remaining and which you are paying for, but never realizing.
- Tanks are commonly exchanged after so many days, regardless of how much water you have used.
- Tanks are exchanged at some point after you call, based on a quality indicator. At this point, the water quality is less than desirable. This can take days.
- Tanks make you dependent on someone else.
With DI cartridges:
- DI cartridge systems eliminate the need for an outside service provider to enter your facility.
- DI cartridges are replaced on your schedule, not the service provider’s.
- DI cartridge systems allow you to keep spare cartridges onsite.
- DI cartridge systems give you back control.
As with DI tanks, DI cartridge systems fed with reverse osmosis water allow for much greater run times before exhaustion/replacement. This would be the case for applications requiring greater than 2 megohm resistivity.
DI cartridges are not a good fit for everyone, but they might be a good fit for you!