NCS Multistage v. Nine Energy: Why a Private Sale May Not Shield Against Later Prior Art

A sale can be commercially public without publicly teaching how an invention works. That distinction now matters twice under the America Invents Act: a sale may create prior-art risk, yet still fail to qualify as the inventor’s “public disclosure” that would protect against an intervening third-party disclosure.

In NCS Multistage Inc. v. Nine Energy Service, Inc., a precedential opinion issued September 14, 2026, the Federal Circuit applied that distinction to a private product sale. The court held that NCS’s earlier sale to one customer did not publicly disclose the invention for the exception in 35 U.S.C. § 102(b)(1)(B). A later third-party sale and use therefore remained prior art. The court also corrected two claim constructions, vacated the infringement, no-invalidity, and damages judgments, and remanded for a new trial.

For inventors and product companies, the decision delivers a practical warning: the U.S. grace period is not a single blanket rule. Its exceptions turn on who made a disclosure, what was disclosed, whether the public could learn the relevant technology, and whether the patent application is entitled to the filing date the owner assumes it has.

Two grace-period exceptions that should not be confused

35 U.S.C. § 102(b)(1) contains two related but different exceptions for disclosures made one year or less before a claimed invention’s effective filing date.

Section 102(b)(1)(A) addresses a disclosure made by the inventor, a joint inventor, or someone who obtained the disclosed subject matter from an inventor. In simplified terms, it can prevent an inventor-originated disclosure during the one-year period from being used as prior art against the inventor’s own application.

Section 102(b)(1)(B) addresses a different sequence. A third party makes an intervening disclosure, but before that disclosure the inventor publicly disclosed the same subject matter. The inventor’s earlier public disclosure can remove the later disclosure as prior art to the extent the statutory requirements are satisfied.

The word “publicly” is central to the second exception. It is not enough to show that the inventor previously engaged in some transaction involving a product. The earlier activity must make the relevant subject matter available to the public. The USPTO’s MPEP § 2153 guidance also cautions that the exception is subject-matter specific: additional subject matter in the intervening disclosure can remain prior art.

What happened in NCS Multistage

The dispute concerned U.S. Patent No. 10,465,445, which relates to a tool used when positioning casing in an oil or gas well. NCS accused Nine Energy of infringing claims involving a rupture-disc assembly. At trial, the jury found infringement, rejected invalidity, and awarded damages.

The prior-art timeline became critical. In July 2012, NCS sold an AirLock device to Tundra. Later in 2012, TCO sold a different device—the TDP-PO tool—to Apache, which subsequently used it. NCS argued that its earlier AirLock sale publicly disclosed the relevant subject matter, bringing the later TCO disclosure within § 102(b)(1)(B).

The Federal Circuit disagreed. It relied on its 2024 precedential decision in Sanho Corp. v. Kaijet Technology International Ltd., which explained that a commercial transaction does not necessarily put the public in possession of the invention. “On sale” and “publicly disclosed” perform different work in the statute.

NCS’s sale had been made privately to a single customer. The device was delivered in a sealed black tube that had to be cut open, and there was no evidence of wide distribution or placement where the public could examine it. Nor was there evidence that the public could determine the relevant claimed features from the product. The absence of a nondisclosure agreement did not, by itself, transform the transaction into a public technical disclosure; the related technical documents were marked confidential.

The court therefore held that no reasonable jury could find NCS’s AirLock sale to be a public disclosure under § 102(b)(1)(B). TCO’s later sale to Apache and Apache’s use of the device were prior art as a matter of law.

A private sale is not automatically safe

The opinion should not be read to mean that private sales are harmless. Under § 102(a)(1), a claimed invention may become prior art through public use, an on-sale event, or other public availability before its effective filing date. The Supreme Court’s Helsinn Healthcare v. Teva Pharmaceuticals decision also confirms that the AIA did not eliminate prior-art consequences for every confidential commercial sale.

NCS Multistage answers a narrower question: whether the inventor’s private sale counted as a prior public disclosure capable of neutralizing a later independent disclosure under § 102(b)(1)(B). It did not.

That creates a dangerous middle ground. A transaction may create patent-timing problems for the seller but still fail to place enough technical information before the public to protect the seller from a competitor’s later disclosure. Inventors should not plan a filing strategy around the assumption that their first customer transaction “locks in” the disclosed subject matter.

Tucker Law’s guide on public disclosure and patent filing explains the broader timing risks surrounding pitches, demonstrations, online posts, and offers for sale. Businesses that have already launched should also review the practical steps in seeking protection after a product reaches the market.

The provisional application did not provide the expected date

The case also illustrates why merely filing a provisional application does not guarantee that every later claim receives the provisional date. The ’445 patent claimed priority to a provisional application filed February 5, 2013. But the Federal Circuit agreed that certain claims lacked support in that provisional application. Those claims were therefore subject to the post-AIA version of § 102.

A provisional application establishes priority only for subject matter it adequately describes and enables. A later nonprovisional claim that introduces unsupported subject matter may receive a later effective filing date, exposing it to intervening references or even changing which statutory regime applies.

This is why a provisional should be treated as a substantive technical disclosure rather than a placeholder cover sheet. The application should capture the invention’s meaningful alternatives, dimensions, components, operating relationships, and contemplated implementations. Tucker Law’s overview of provisional patent applications describes the filing’s role and the twelve-month path to a nonprovisional application.

Before relying on a priority date in prosecution, licensing, diligence, or litigation, counsel should map each important claim limitation back to the earlier application. Tucker Law’s patent-application practice focuses on building disclosures that support both prosecution and later enforcement.

The court also rejected claim constructions that rewrote the patent

The prior-art ruling was not the only reason the judgment fell. The Federal Circuit also found error in the construction of “internal diameter” and “casing string.”

For “internal diameter,” the court concluded that the ordinary meaning was a measured diameter across the width of the casing string, not an inner surface. That correction required a new infringement trial because factual disputes remained under the proper construction.

The district court had also construed “casing string” to refer to pipe customarily at least 4.5 inches in outer diameter. Although industry evidence showed that 4.5 inches was a common size, the specification used permissive language and expressly contemplated other dimensions. The Federal Circuit held that the intrinsic record did not justify importing the size limitation. Extrinsic catalogs could not override what the patent itself said.

This part of the opinion offers a drafting lesson that complements the priority-date lesson. Examples, preferred dimensions, and industry conventions should be described deliberately. Words such as “may,” “for example,” and “about” can preserve breadth, while repeated statements of necessity may later be used to narrow a claim. Patent drafting is not only about satisfying the USPTO; the document may eventually be parsed word by word in patent litigation.

What inventors and companies should do before a sale or disclosure

The safest practice remains filing before an offer, shipment, demonstration, investor presentation, crowdfunding campaign, or technical handoff. When commercial timing makes that impossible, the company should identify exactly what will be disclosed, to whom, and under what restrictions before the transaction occurs.

A sound process should include a written invention timeline, dated copies of technical materials, confidentiality terms where appropriate, and a record of what a recipient could actually inspect or learn. Confidentiality can preserve options, but it is not a substitute for filing. U.S. grace-period exceptions are technical and fact-dependent, and many foreign jurisdictions are less forgiving of pre-filing disclosures.

Companies should also distinguish between a disclosure that originated with an inventor and one that was actually made public. If a third party may publish or sell similar technology, relying on § 102(b)(1)(B) requires evidence that the inventor’s earlier disclosure made the relevant subject matter publicly available—not merely that an earlier private deal occurred.

Finally, audit provisional support before important deadlines or transactions. Product evolution after an early filing may require another application. A weak priority assumption can affect patentability, freedom-to-operate decisions, valuation, licensing leverage, and litigation strategy.

The practical takeaway

NCS Multistage reinforces a disciplined sequence: file a sufficiently detailed application, control pre-filing disclosures, and document the facts rather than relying on the phrase “one-year grace period.” A private sale may qualify for one statutory analysis while failing another. The labels attached to a transaction matter less than what the public could actually learn and what the application actually supports.

If a product has been sold, demonstrated, delivered to a customer, or disclosed before filing, contact Tucker Law promptly. A registered patent attorney can reconstruct the timeline, evaluate the applicable § 102 exceptions, review provisional support, and identify the filing options that remain.

This article provides general legal information and is not legal advice. Patentability and priority depend on the complete facts, claim language, disclosure content, dates, and applicable law.