Federal Circuit Vacates Summary Judgment on Patent Inequitable Conduct and USPTO Disclosure Issues

The Federal Circuit’s February 26, 2026 decision in Global Tubing LLC v. Tenaris Coiled Tubes LLC is an important reminder that patent inequitable conduct claims are difficult to win on summary judgment. The case involved alleged failures to disclose internal documents to the U.S. Patent and Trademark Office, or USPTO, during prosecution of patents covering coiled tubing technology used in the oil and gas industry.

The court vacated a district court ruling that had found inequitable conduct as a matter of law and sent the case back for further proceedings. The opinion highlights two recurring issues in patent prosecution and patent litigation: disclosure obligations to the USPTO and the demanding proof required to show specific intent to deceive.

Background

The dispute involves coiled steel tubing, a product used primarily in horizontal oil and gas wells. In the 1990s, Southwestern Pipe developed a quenched-and-tempered coiled tubing product called CYMAX. Quenching and tempering is a heat-treatment process designed to improve strength and durability.

In 2006, Tenaris acquired Southwestern’s assets, including equipment and internal documents describing the CYMAX manufacturing process. According to the Federal Circuit, those materials disclosed a version of CYMAX with a carbon range of 0.13 to 0.17 wt. % and a yield strength of 100 ksi.

Years later, Tenaris developed its BlueCoil product and obtained patents directed to quenched-and-tempered coiled tubing, including U.S. Patent No. 9,803,256. Global Tubing later introduced a competing product, DURACOIL.

The inequitable conduct issue centered on whether Tenaris should have disclosed the internal CYMAX documents to the USPTO during prosecution of the ’256 patent. The Federal Circuit noted that the claimed carbon range in the patent overlapped at least in part with the range described in those documents.

During prosecution, Tenaris submitted hundreds of references to the USPTO, including a paper describing CYMAX-related manufacturing and testing. But it did not submit the full internal CYMAX documents with the application that led to the ’256 patent.

The patent examiner initially rejected the claims as obvious. In general, an obviousness rejection means the examiner believes the claimed invention would have been an expected variation of what was already known.

To respond, Tenaris submitted an expert declaration stating that CYMAX’s carbon chemistry was outside the claimed range. The Federal Circuit observed that this statement was incorrect because the two ranges overlapped at 0.17 wt. %.

The record also included an internal comment from the expert: “I am not sure it is a good idea to disclose this document.” That statement later became a focal point in the inequitable conduct dispute.

The USPTO allowed the patent without the examiner having the full CYMAX documents before him.

Later, when related applications were prosecuted by different counsel, the CYMAX documents were provided to that firm. According to the opinion, the new attorneys advised that the documents should be disclosed and could affect validity.

Tenaris eventually disclosed part of the CYMAX materials in later prosecution, but initially omitted several pages. The complete set was later submitted in connection with additional related patents.

After a market dispute developed, Global Tubing filed a declaratory judgment action seeking a ruling that its DURACOIL product did not infringe. A declaratory judgment action allows a party to ask a court to resolve a legal dispute before waiting to be sued.

During discovery, Tenaris produced internal communications, including the expert’s statement about whether disclosure was “a good idea.” Global Tubing then added an inequitable conduct claim.

What the court decided

The district court had granted summary judgment to Global Tubing on inequitable conduct. On appeal, the Federal Circuit vacated that ruling.

The appellate court explained that inequitable conduct requires clear and convincing evidence that at least one named individual withheld material information with a specific intent to deceive the USPTO. On summary judgment, however, courts must view the evidence in the light most favorable to the nonmoving party.

Because Tenaris was the nonmoving party on this issue, the question was not whether Global Tubing had a strong record. The question was whether the record left room for a reasonable factfinder to infer something other than intent to deceive.

The Federal Circuit held that the district court did not properly apply that summary judgment standard. In the panel’s view, the evidence had to be read in Tenaris’s favor at that stage, and doing so revealed a genuine dispute of material fact on intent.

The result was not a win for Tenaris on the merits. Instead, the case was sent back for further proceedings because the inequitable conduct issue could not be decided as a matter of law on the existing summary judgment record.

Court’s reasoning

• The key issue was intent. Inequitable conduct is not established by a material omission alone. The challenger must also prove a deliberate plan to mislead the USPTO.
• The internal statement about whether disclosure was “a good idea” was important, but it was not dispositive on summary judgment. The Federal Circuit held that the statement could support competing inferences.
• The court also pointed to evidence that could support Tenaris’s position, including testimony that the expert believed the CYMAX information was cumulative of other references and that he was mistaken, not deceptive, about the overlap in carbon ranges.
• Because summary judgment requires courts to draw reasonable inferences for the nonmoving party, the district court could not resolve that intent question without a trial or other factfinding.

Practical implications for patent prosecution and patent litigation

This decision is a useful reminder that inequitable conduct remains difficult to prove, especially at the summary judgment stage. Even where the record contains damaging internal language, courts must still ask whether the evidence compels the single most reasonable inference of intent to deceive.

For patent owners and applicants, the case underscores the value of disciplined disclosure practices. Internal technical materials, legacy documents obtained in acquisitions, and communications about whether to submit references can become central evidence later. Companies should review inherited files carefully, document good-faith disclosure analyses, and ensure that inventors, in-house counsel, and outside counsel are aligned on material prior art decisions.

The case also highlights a recurring litigation risk: informal emails or technical comments may be read very differently in hindsight. Teams involved in patent prosecution should assume that internal statements about disclosure decisions may later be examined closely in discovery.