IP Law Daily, PATENT—Fed. Cir.: Inequitable conduct and Walker Process rulings vacated in coiled tubing dispute, (Feb 26, 2026)

By Saurabh Kashyap, B.A., M.A., LL.B., LL.M.

The district court erred by resolving disputed issues of intent, materiality, and relevant market definition at summary judgment despite genuine disputes of material fact.

The U.S. Court of Appeals for the Federal Circuit has vacated a federal district court’s grant of summary judgment finding inequitable conduct in the procurement of three coiled tubing patents and also vacated summary judgment rejecting a Walker Process attempted monopolization claim in a precedential decision. The appellate court held that genuine disputes of material fact precluded summary judgment on both issues, particularly as to whether the inventor acted with specific intent to deceive the U.S. Patent and Trademark Office (PTO) and whether the withheld prior art was but-for material. It further concluded that the district court erred in resolving, as a matter of law, the contested issues concerning the relevant antitrust market and the dangerous probability of monopolization. The Federal Circuit affirmed only the denial of summary judgment to the patent holder on inequitable conduct, finding that the evidence could support a fraud determination at trial (Global Tubing LLC v. Tenaris Coiled Tubes LLC, No. 23-1882 (Fed. Cir. Feb. 26, 2026)).

Background. The plaintiff/cross-appellant Global Tubing LLC manufactures quenched-and-tempered coiled tubing products for the oil and gas industry under the name DURACOIL. The defendant/appellant, Tenaris Coiled Tubes LLC, also competes in that market and produces a similar product, BlueCoil. The dispute arose after Tenaris acquired legacy assets related to a prior coiled tubing product, CYMAX, and later secured patents covering its BlueCoil technology.

The asserted patents were U.S. Patent Nos. 9,803,256 (the ’256 patent), 10,378,074 (the ’074 patent), and 10,378,075 (the ’075 patent). The ’256 patent claims a coiled steel tube manufactured by a full-body heat-treatment process, with a specified chemical composition including 0.17–0.35 wt.% carbon and a yield strength greater than about 80 ksi. The ’074 patent is a continuation of the ’256 patent, and the ’075 patent is a divisional of it; both contain similar carbon ranges and structural limitations.

Global Tubing filed suit in October 2017 in the Southern District of Texas seeking a declaratory judgment that its DURACOIL product did not infringe the ’256 patent. Tenaris counterclaimed for infringement of the ’256, ’074, and ’075 patents. During discovery, Global Tubing obtained communications between Tenaris inventors and prosecution counsel concerning legacy “CYMAX Documents,” which disclosed a carbon range of 0.13–0.17 wt.% and a yield strength of 100 ksi. Those documents were not submitted during the prosecution of the ’256 patent. Global Tubing amended its complaint to assert inequitable conduct and fraud under Walker Process Equipment, Inc. v. Food Machinery & Chemical Corp., 382 U.S. 172 (1965). The district court granted summary judgment on the Walker Process claim to Tenaris and granted summary judgment on the inequitable conduct claim to Global Tubing. Both parties appealed.

Inequitable conduct. The Federal Circuit held that the district court improperly resolved disputed questions of intent at summary judgment. To establish inequitable conduct, a challenger must prove by clear and convincing evidence that an individual acted with specific intent to deceive the PTO and that the withheld information was but-for material. Citing Therasense, Inc. v. Becton, Dickinson & Co., 649 F.3d 1276 (Fed. Cir. 2011) (en banc), the court reiterated that deceptive intent must be “the single most reasonable inference” from the evidence.

The district court relied heavily on a comment by inventor Dr. Martín Valdez in a draft declaration: “I am not sure it is a good idea to disclose this document,” referring to the CYMAX materials. The lower court characterized this statement as rare direct evidence of intent to defraud.

The Federal Circuit disagreed with the summary disposition. It emphasized that at summary judgment, courts must draw all reasonable inferences in favor of the nonmoving party. Dr. Valdez testified that he believed the CYMAX carbon range was outside the claimed range and that he thought the earlier Chitwood reference already disclosed equivalent information. Although his understanding of range overlap was legally mistaken—overlapping endpoints can render claims prima facie obvious under In re Geisler, 116 F.3d 1465 (Fed. Cir. 1997)—the court held that a reasonable factfinder could credit his explanation as confusion rather than deceit.

Because competing inferences were plausible and credibility determinations were required, summary judgment on intent was improper. The court cited Paragon Podiatry Lab., Inc. v. KLM Labs., Inc., 984 F.2d 1182 (Fed. Cir. 1993), cautioning that inequitable conduct rarely lends itself to summary judgment when intent is disputed.

Materiality and cumulativeness. The appellate court also found a genuine dispute as to but-for materiality. Under Cal. Inst. of Tech v. Broadcom Ltd., 25 F.4th 976 (Fed. Cir. 2022), and Regeneron Pharmaceuticals, Inc. v. Merus N.V., 864 F.3d 1343 (Fed. Cir. 2017), a withheld reference is not material if it is merely cumulative of prior art already before the examiner.

Tenaris argued that the Chitwood paper, which was disclosed, described low-carbon 4100-series steel with a 100 ksi yield strength and referenced ASTM standards from which the specific chemical composition could be derived. A reasonable factfinder could conclude that a skilled artisan would understand the carbon content from publicly available standards, rendering the CYMAX Documents cumulative.

Additionally, during the prosecution of later “grandchild” applications, Tenaris submitted the full CYMAX Documents and still obtained allowance after amendments. A reasonable jury could infer from those later grants that the earlier patents would have issued even had the documents been disclosed. Although Global Tubing offered contrary inferences, the Federal Circuit held that summary judgment was inappropriate given the factual disputes.

Walker Process fraud. Turning to the antitrust claim, the court held that summary judgment in Tenaris's favor was also premature. A Walker Process claim requires proof of fraudulent procurement and the elements of attempted monopolization under Section 2 of the Sherman Act, including a dangerous probability of achieving monopoly power.

The district court concluded that Tenaris, which allegedly held approximately 29% market share, was too small a market participant to pose a significant probability of monopolization. The Federal Circuit found this reasoning legally flawed because the court failed to define the relevant product and geographic market—a prerequisite under Walker Process and Delano Farms Co. v. California Table Grape Commission, 655 F.3d 1337 (Fed. Cir. 2011).

The parties presented competing market definitions: Global Tubing urged a U.S.-only, quenched-and-tempered coiled tubing market; Tenaris proposed a broader global market that included conventional tubing and stick pipe. Because market definition is a fact-intensive inquiry, summary judgment was improper. The court further noted that attempted monopolization does not require a fixed minimum market share and cited Domed Stadium Hotel, Inc. v. Holiday Inns, Inc., 732 F.2d 480 (5th Cir. 1984), warning against a rigid “numbers game.”

The record also contained evidence that Tenaris allegedly threatened litigation at a 2017 trade show and prepared internally for a patent enforcement campaign. If a jury were to find fraudulent procurement, those actions could constitute anticompetitive conduct.

Disposition. Thus, the Federal Circuit vacated the summary judgment of inequitable conduct and the summary judgment rejecting Walker Process liability, affirmed the denial of Tenaris’ motion for summary judgment of no inequitable conduct, and remanded for further proceedings. Each party was ordered to bear its own costs.

The Case is No. 23-1882.

Judge: Stark, L.

Attorneys: Jeffrey A. Lamken (MoloLamken LLP) for Global Tubing LLC. William H. Burgess (Kirkland & Ellis LLP) for Tenaris Coiled Tubes LLC.

Companies: Global Tubing LLC; Tenaris Coiled Tubes LLC

MainStory: TopStory Patent FedCirNews GCNNews