How to Properly Connect a White Ink CISS to Dampers and a Circulation Pump (ET-8550 / DTF Setup)

Question:
A customer asked how to connect two white ink tanks from a CISS to the dampers and circulation pump when setting up a white-ink system for an Epson ET-8550-style DTF conversion. They mentioned purchasing parts from us but noted that there were no instructions included. They also referenced our video "Avoid 3 Costly Mistakes: ET-8550 Printhead FFC Replacement Do's and Don'ts."
They want to understand the correct way to connect the white ink supply, the dampers, and the circulation pump.

Answer

Understanding What You Purchased

You mentioned purchasing components from us-tubes, connectors, and similar parts. Since BCH Technologies sells individual components rather than complete CISS or pre-assembled circulation systems, the setup process usually requires a DIY approach. That's why instructions aren't included by default, as configurations can vary widely based on each user's printer model and workflow.

Why You Won't Use Epson's Two White Tanks

On printers like the ET-8550, Epson includes two internal white tanks in the original design. However, when converting the machine for DTF, you should not use these two tanks at all for white ink circulation. They cannot support continuous mixing, sediment control, or proper flow required for DTF white.

Instead, your white-ink supply should consist of:

• One external white ink tank

• One mixer (stirring unit)

• One circulation pump

This combination keeps white ink continuously moving to prevent settling-something Epson's native tanks cannot do.

How to Connect the CISS White Ink Line to Dampers and Pump

To build the correct flow path, you'll need to create what many users call an H-shaped manifold using two T-connectors.

Here's how to lay it out:

1. Start from your main external white ink tank
   This is your ink reservoir feeding the system.

2. Ink flows into the mixer
   The mixer keeps titanium dioxide in suspension.

3. From mixer → into the circulation pump
   The pump recirculates white ink constantly.

4. From the pump → to the T-connector assembly
   This is where the "H-shape" comes in.

Building the "H"

Imagine the connection like this:

   |--- Damper 1
===T===
   |--- Damper 2
       T===

• The center line (the long part of the "H") is your main feed line from the pump.

• Each leg of the T splits off to a damper-one line for each white channel on the printhead.

• This allows balanced flow to both dampers.

The goal is to ensure both dampers receive equal pressure and fresh, agitated white ink at all times.

What to Search for on YouTube

Since your setup is a custom-built system and not a standardized kit, the best way to learn the fundamentals of constructing a DIY circulation system is to search YouTube for:

"how to make a white ink circulation system"

This will give you general design principles, which you can apply using the parts you purchased.

When you're ready to connect the ink lines directly to the printhead, the T-connector "H layout" above is the correct approach.

Additional Notes

Addressing printer issues can be complicated due to the hands-on nature of the repairs. Because of this, we're not able to provide remote troubleshooting or step-by-step repair support. We do, however, offer in-person evaluations through our local diagnostic facility:
BCH Technologies Printer Repair Service (https://bchtechnologies.com/printer-repair-service).
Due to high demand, service is first-come, first-served, and it may take a few weeks for intake. Our services cover full-printer repairs or individual component repairs, depending on your needs. That said, we know these services can be more costly than DIY options, so we strongly recommend beginning with online research. A great place to start is our YouTube channel homepage:
BCH Technologies on YouTube (https://youtube.com/@bchtechnologies).
Use the search icon near the "About" tab to quickly find videos related to your specific setup or issue. We've uploaded hundreds of videos over nine years, making it difficult to recall each one individually, so the search tool is your best resource. YouTube may also recommend helpful videos from other channels.

Thank you again for contacting us and for supporting BCH Technologies. We truly appreciate your patience and your commitment to learning the technical side of DTF printing. If you have additional questions or need clarification on any part of the process, feel free to reach out anytime.