High-Pressure Diesel Fuel Injection Lines


Looking for high-pressure diesel fuel injection lines? If so, you’ve come to the right place.

Dynamic Tube has been in continuous operation in Maquoketa, IA for over 40 years. In the beginning, DTI was purely a manufacturer of diesel lines.

Over the years, DTI has added capabilities that now include mandrel bending, pipe welding, brazing, and light assembly. 

But all along, Dynamic Tube has never stopped producing high-pressure diesel fuel injection lines. All told, DTI still manufactures many thousands of diesel lines every year.

How do we do it?  

In order to manage that high level throughput, DTI has established the right systems, equipment, and supply chain to make world class parts quickly, efficiently, and backed by ISO9001:2015 quality assurance.

Raw Material Management

In order to make any tubing part, the process first begins with raw tubing stock and material order management. As such, we’ve developed processes that allow us to navigate the long lead times, tariffs, and supply chain disruptions common to steel tubing.

When it comes to diesel fuel injection parts, DTI also maintains an inventory of certified carbon and stainless fuel-tubing that includes ODs of 1/4″, 5/16″, 3/8″, 4mm, 6mm, 8mm, as well as other material like 1010, ST52, and PP600.

Setting Up the Build

Once a part has been quoted, and a purchase order has been received, the job can begin. At that point, the first step is to enter the XYZ bend data into our secure project Bend Pro software system.

Keep in mind, our bend machinery can perform multiple radius bends on one line (although we could have a friendly debate about whether that’s best practice from an engineering design standpoint).

We install the XYZ data of each part into our Bend Pro software, which synchronizes with our tube benders. From there, the fabrication process flies.

Our Fabrication Process

First, we cut the raw tubing to length. Next we deburr, chamfer, and prep the tube ends. The tubes then get sleeves. Then we end-form the tubes. End-forms can take many shapes, depending on the application. These include:

  1. A fitting (there are countless options).
  2. A preset fitting, or ermeto endform.
  3. Or a braze-on, banjo fitting.

After the tube has been properly end-formed, we bend the part per print.

At this point in the process, they look like parts. However, the job isn”t done yet.

Testing, Auto-Frettage, and Cleaning

First, the shape of the part is verified to specification using one of our state of the art Romer CMM’s.

If required, DTI has an autofrettage machine that will pre-stress diesel line parts with up to 140,000 PSI. Ultimately, the pre-stress autofrettage process results in superior part strength– and fatigue resistance.

Finally, we clean all diesel lines on our automatic flush stand. Still not done. After clean, we inspect and patch-test parts to meet clean specs.

When required, at this stage we can also perform additional light-assembly. In that case, we’ll group several parts together, and install clamps or brackets to create a complete fuel assembly. 

Throughout the entire fabrication process, we follow ISO9001:2015 standards to ensure the quality of our parts.

Pack and Ship

Diesel parts move from clean to our dedicated shipping area. Once in shipping, we package, label, and ship parts according to spec. When requested, we can ship using an OEM’s packaging or labels, either to a warehouse or direct to an end-user. 

DTI also interfaces with logistics. We schedule freight pick-ups with carriers, deliver parts ourselves when feasible, and frequently go above and beyond to get the job done for our customers.  

In summary, our diesel area is a microcosm of Dynamic Tube. Put another way, every part we manufacture at DTI follows a similar journey as our diesel lines.

That said, if you have a high-pressure diesel fuel injection lines to outsources, contact us today. If you’re a North American OEM looking for a reliable, long term supplier-partnership to bolster your supply chain– Dynamic Tube wants to work with you. Let’s talk!

Call us at 563-652-5165 to say hello, or email your prints directly to