24V Peristaltic Pump Tubing Replacement and Recommended White Ink Circulation Speed

Question

I purchased a 24V peristaltic pump for circulating white ink, but the tubing inside the pump has developed a tear and now needs attention.

What size and type of tubing should be used inside this pump, including the inside diameter, outside diameter, wall thickness, or tubing designation? Does BCH Technologies sell replacement pump tubing, or is there a recommended source for purchasing it?

I would also like to know what controller setting or pump speed is recommended for maintaining effective white ink circulation without placing unnecessary stress on the tubing or ink system.

Answer

At this time, BCH Technologies does not sell replacement tubing specifically for the internal compression section of this peristaltic pump. The tubing inside a peristaltic pump is a wear item because it is repeatedly compressed by the pump rollers. Over time, this constant squeezing can cause the tubing to flatten, harden, crack, or tear, especially when it is exposed to white ink, cleaning solution, heat, excessive pump speed, or continuous operation.

Before replacing the entire tube, you may be able to make a temporary repair if the damaged area is limited to the section being compressed by the rollers. Open the pump housing carefully, inspect the full length of the internal tubing, and determine whether there is enough undamaged tubing available. In many cases, you can cut off the torn section and reposition the tubing slightly so that a fresh area sits beneath the rollers.

This approach only works when the remaining tubing is still flexible, has no additional cracks, and is long enough to reconnect securely without being stretched or kinked. If the tubing has become brittle, swollen, flattened, discolored, or damaged in more than one location, replacing the complete internal tube is the safer option.

Determining the Correct Tubing Size

We do not recommend purchasing tubing based solely on a general pump description such as "24V peristaltic pump." Pumps that look nearly identical may use different tubing sizes, roller clearances, and pump-head designs.

The most reliable method is to remove the original tubing and measure it directly with a digital caliper. You will need to measure:

• The inside diameter, which controls the ink flow capacity

• The outside diameter, which determines whether the rollers can compress the tubing correctly

• The wall thickness, calculated as half the difference between the outside and inside diameters

• The total tube length required inside the pump head

• The tubing diameter needed to fit the pump's inlet and outlet connectors

For example, two tubes may have the same inside diameter but different outside diameters. The thicker tube may place too much pressure on the motor and rollers, while the thinner tube may not close completely during compression. If the tubing does not fully close, the pump may lose suction, allow backflow, or fail to move the white ink properly.

The replacement tubing should closely match the original tubing in all dimensions. Even a small difference in outside diameter or wall thickness can change the pump's performance and shorten the tubing's life.

Choosing the Correct Tubing Material

The replacement tube must be flexible enough for repeated compression and chemically compatible with the white ink or circulation fluid being used. Depending on the ink formulation, suitable peristaltic-pump tubing may be made from silicone, PharMed-type material, Santoprene-type material, or another flexible chemical-resistant elastomer.

However, not every silicone tube is suitable for long-term contact with DTF white ink. Some tubing may swell, soften, harden, or release particles after prolonged exposure to the ink vehicle or cleaning solution. Generic aquarium tubing, air-line tubing, or soft PVC tubing may fit physically but may not survive continuous roller compression or chemical exposure.

When purchasing replacement tubing, look for tubing specifically described for use in peristaltic pumps. Provide the supplier with the measured inside diameter, outside diameter, wall thickness, and the type of liquid being pumped. Industrial tubing suppliers, laboratory pump suppliers, chemical-handling suppliers, and some DTF equipment parts vendors may carry suitable material.

It is helpful to purchase enough tubing for several replacements because the section inside the pump head will eventually wear again. Keep the extra tubing sealed and protected from dust, heat, sunlight, and chemical contamination.

Inspecting the Pump Before Installing New Tubing

A torn tube may be caused by normal wear, but it can also indicate excessive compression or a mechanical problem. Before installing replacement tubing, inspect the inside of the pump head carefully.

Check the rollers for sharp edges, dried ink, hardened residue, rust, or rough surfaces. A damaged roller can repeatedly cut or abrade new tubing. Also inspect the pump housing and tubing channel for burrs or pinching points.

Make sure the rollers rotate freely. If one roller is seized or dragging, it can pull and scrape the tubing instead of rolling smoothly over it. Clean any white ink residue from the pump head, but avoid using a chemical that could damage the plastic housing or remaining tubing.

The replacement tube should sit naturally in the pump channel without twisting. Avoid stretching the tube tightly during installation. A stretched tube has thinner walls and may tear prematurely. At the same time, do not leave excessive slack that can fold, kink, or become caught by the rollers.

After installation, run the pump briefly at a low speed and observe the tubing. Confirm that the rollers compress the tube smoothly and that the tube does not walk sideways, bunch up, or pull away from the connectors.

Recommended Pump Speed for White Ink Circulation

There is no single universal speed setting for every 24V white ink circulation pump. The correct setting depends on several factors, including:

• The controller board used in the machine

• The pump motor and gearbox

• The length and inside diameter of the circulation tubing

• The size of the white ink bottle or tank

• The viscosity and formulation of the white ink

• The height difference between the pump and the ink container

• The design of the circulation return line

• Whether the system runs continuously or intermittently

In most installations, the pump is controlled by the machine's controller board rather than being operated directly at full 24V continuously. Different machines and conversion systems use different voltage levels, pulse-width modulation settings, timers, or duty cycles. For that reason, a setting that works well on one machine may circulate too slowly or too aggressively on another.

The goal is gentle, continuous, or periodic circulation-not high-pressure pumping. The white ink should move enough to reduce pigment settling, but it should not foam, splash, generate excessive bubbles, or create strong suction at the bottom of the ink container.

Start at the lowest setting that produces visible and consistent ink movement through the return line. Increase the speed gradually only if the white ink is not circulating adequately. A slow, steady flow is generally preferable to a fast flow.

Running the pump too quickly can cause several problems:

• Accelerated wear and tearing of the internal pump tubing

• Foaming or aeration of the white ink

• Air bubbles entering the ink delivery system

• Excessive heat in the pump motor or tubing

• Strong suction that pulls settled pigment or debris from the bottom of the bottle

• Increased pressure at fittings, connectors, and return lines

• Premature motor or controller-board failure

The circulation tube inside the white ink bottle should normally remain slightly above the very bottom of the container. White pigment may form heavier sediment or hardened material near the bottom, even when the ink is mixed regularly. Allowing the intake tube to rest directly against the bottom may cause the system to pull concentrated sediment or dried particles into the circulation line.

You should see gentle movement in the white ink without a vortex, strong bubbling, or violent agitation. If the ink is foaming or the tubing is pulsing aggressively, reduce the pump speed.

Continuous Versus Intermittent Operation

Some DTF systems circulate white ink continuously while the printer is powered on. Others operate the pump on a timed cycle. Either method can work when the system is designed correctly.

Continuous operation provides steady ink movement but increases wear on the pump tubing. Intermittent operation can extend tubing life, but the off-cycle must not be so long that the white pigment settles excessively.

The correct timing is determined by the machine design, ink type, tubing layout, and controller board. If your machine already includes a dedicated controller, it is generally best to begin with the controller's intended factory or supplier setting rather than bypassing it and connecting the pump directly to a constant 24V power supply.

If you are using an adjustable controller, begin at a low duty cycle and monitor the ink movement, tubing temperature, pump noise, and motor temperature. The pump should not become excessively hot, and the tubing should not show rapid flattening or surface damage.

Warning Signs That the Speed Is Too High

Reduce the pump setting if you notice any of the following:

• White ink is foaming in the bottle

• Large numbers of bubbles are visible in the circulation line

• The pump tubing becomes hot

• The pump makes a loud clicking, grinding, or strained sound

• The tube repeatedly moves sideways inside the pump head

• The inlet tube collapses under suction

• The return flow splashes heavily

• The tubing develops another tear within a short period

• The pump motor or controller becomes unusually hot

• Ink leaks from fittings or connectors

A recurring tear should not be treated as a tubing-only issue. It may indicate that the tubing is the wrong size, the roller pressure is too high, the pump is running too fast, the pump head has a sharp edge, or the tubing material is not suitable for peristaltic use.

Testing After Repair

After repositioning or replacing the tubing, test the pump with close supervision before returning it to unattended operation.

Check all fittings for leaks and confirm that the circulation direction is correct. Make sure the pump draws ink from the intended line and returns it through the correct line. Watch the flow for several minutes and confirm that no air is entering through loose connections.

Continue checking the repaired tubing during the first several hours and again after the first few days. Look for flattening, cracks, whitening, swelling, or movement inside the pump head. A properly sized tube should compress completely under the roller and then recover its shape after the roller passes.

Because a peristaltic pump tube is expected to wear over time, regular inspection should be included in the machine's maintenance routine. The replacement interval will vary greatly depending on pump speed, operating hours, tubing material, ink chemistry, and roller pressure.

Addressing printer and DTF equipment problems can be complicated because many issues require direct, hands-on inspection. For that reason, we are unable to provide individualized remote troubleshooting, repair instructions, or ongoing technical support for printer repairs.

We do offer in-person evaluation and repair through our local printer diagnostic and repair facility [https://bchtechnologies.com/printer-repair-service]. Due to high demand, repairs are handled on a first-come, first-served basis, and it may take several weeks before an appointment or drop-off opening becomes available. Our services can cover either a complete printer or certain removable components, and the service page provides instructions on how to proceed.

We also recognize that professional repair services may not be the most economical choice for every situation. For that reason, we strongly encourage customers to use online research and self-help resources whenever they feel comfortable doing so. You can begin by searching YouTube or visiting the homepage of our BCH Technologies YouTube channel [https://youtube.com/@bchtechnologies].

On the channel homepage, use the search icon located near the "About" section on the right side of the menu bar to search for the exact pump, printer model, circulation system, or repair topic. We receive dozens of requests each day asking whether we have a video about a particular issue. Since we have produced technical videos for more than nine years, it is difficult to remember every video by title. Using YouTube's search feature is usually the fastest and most effective method. YouTube may also recommend useful videos from other repair and DTF channels.

Thank you again for contacting BCH Technologies and for supporting our work. We appreciate your patience and hope this information helps you repair the pump, select suitable replacement tubing, and establish a gentle circulation rate that protects both the white ink and the pump components.