DCT

4:26-cv-05523

Flowco Productions LLC v. Liberty Lift Solutions LLC

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Amended Complaint
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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: Flowco Productions LLC v. Liberty Lift Solutions LLC, 4:26-cv-05523, S.D. Tex., 10/08/2026
  • Venue Allegations: Venue is alleged to be proper based on Defendant having a regular and established place of business within the Southern District of Texas and committing acts of infringement in the district, including advertising, offering to sell, and selling the accused products.
  • Core Dispute: Plaintiff alleges that Defendant’s plunger lift systems, specifically its Dart and Diamond Plungers and its Lubricators, infringe six U.S. patents related to components for oil and gas well plunger lift devices.
  • Technical Context: The technology concerns plunger lift systems, which are mechanical devices used in the oil and gas industry to remove fluid accumulation from wells to maintain and maximize production.
  • Key Procedural History: Plaintiff alleges it provided Defendant with written notice of infringement and, subsequently, element-by-element claim charts for several of the patents-in-suit beginning in September 2024, over two years prior to the filing of the current amended complaint. An original complaint was filed in July 2026, a copy of which was provided to Defendant's counsel.

Case Timeline

Date Event
2015-02-20 Priority Date for '785, '133, '189 Patents
2015-05-18 Priority Date for '849, '327 Patents
2017-01-01 Approximate date Flowco began marketing lubricator practicing '849 and '327 Patents
2018-03-13 '133 Patent Issued
2018-05-01 '785 Patent Issued
2018-11-30 Priority Date for '267 Patent
2019-03-05 '849 Patent Issued
2020-07-21 '327 Patent Issued
2021-08-31 '189 Patent Issued
2022-04-05 '267 Patent Issued
2024-09-05 Flowco sent written notice to Liberty Lift regarding '785, '133, '189 Patents
2024-09-17 Liberty Lift acknowledged receipt of notice letter
2025-08-28 Flowco provided claim charts for '785, '133, '189 Patents to Liberty Lift
2025-09-17 Liberty Lift responded through counsel regarding patents
2026-07-13 Flowco filed original complaint
2026-07-16 Flowco provided copy of original complaint to Liberty Lift's counsel
2026-08-01 Approximate date Flowco learned Liberty Lift was supplying the accused Lubricator
2026-10-08 First Amended Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 9,957,785 - "Unitary Body Bypass Plunger And Valve Cage"

  • Patent Identification: U.S. Patent No. 9,957,785, "Unitary Body Bypass Plunger And Valve Cage," issued May 1, 2018 Compl. ¶20

The Invention Explained

  • Problem Addressed: The patents related to the '785 Patent describe problems with prior art plungers, including their complexity and susceptibility to failure in the harsh downhole environment of an oil or gas well e.g., '133 Patent, col. 1:25-2:24 '189 Patent, col. 1:21-2:14
  • The Patented Solution: The patent proposes a bypass plunger where the "hollow plunger body and valve cage" are "formed as one integrated piece" Compl. ¶27 This "unibody" construction is intended to simplify the design and improve durability by eliminating joints between components, which are common points of failure (e.g., '189 Patent, col. 5:14-22). The plunger houses a reciprocating dart valve and a clutch assembly to control fluid bypass during operation Compl. ¶27
  • Technical Importance: Creating the main plunger body and valve cage from a single, integrated piece of material sought to enhance reliability and reduce manufacturing complexity compared to multi-part, assembled devices.

Key Claims at a Glance

  • The complaint asserts independent claim 1 Compl. ¶112
  • The essential elements of claim 1 include:
    • a hollow plunger body and valve cage formed as one integrated piece, with the valve cage enclosing a dart valve and a split bobbin clutch assembly;
    • a partition nut for adjustably spacing the dart valve and clutch assembly;
    • a dart valve that reciprocates within the valve cage; and
    • a retaining device that threads into the valve cage Compl. ¶27
  • The complaint also asserts dependent claims 2-10 Compl. ¶112

U.S. Patent No. 9,915,133 - "Unibody Bypass Plunger With Centralized Helix and Crimple Feature"

  • Patent Identification: U.S. Patent No. 9,915,133, "Unibody Bypass Plunger With Centralized Helix and Crimple Feature," issued March 13, 2018 Compl. ¶29

The Invention Explained

  • Problem Addressed: The patent background identifies that conventional bypass plungers are complex and suffer from reliability issues due to the high impact forces, caustic fluids, and elevated temperatures of the downhole environment '133 Patent, col. 1:25-2:24
  • The Patented Solution: Like the '785 patent, this invention describes a "unitary hollow plunger body and valve cage formed in one integrated piece" '133 Patent, claim 1 It adds specific features, including a "helical groove" on the plunger body to induce spin and prevent uneven wear, and "crimples to lock the retaining nut," providing a secure method for fastening components '133 Patent, abstract '133 Patent, col. 3:1-17
  • Technical Importance: The claimed combination of a unitary body, a spin-inducing helix, and a secure crimp-locking feature represented an effort to create a more durable, reliable, and efficiently operating plunger.

Key Claims at a Glance

  • The complaint asserts independent claim 1 Compl. ¶120
  • The essential elements of claim 1 include:
    • a unitary hollow plunger body and valve cage formed in one integrated piece;
    • a poppet valve reciprocatingly disposed within the valve cage;
    • a partition nut for locating a clutch;
    • a clutch formed of a split bobbin secured by at least one garter spring; and
    • a retaining nut to hold the poppet valve and clutch within the valve cage Compl. ¶36
  • The complaint also asserts dependent claims 2-16 Compl. ¶120

U.S. Patent No. 11,105,189 - "Unibody Bypass Plunger And Valve Cage"

  • Patent Identification: U.S. Patent No. 11,105,189, "Unibody Bypass Plunger And Valve Cage," issued August 31, 2021 Compl. ¶38
  • Technology Synopsis: The patent describes a bypass plunger with a "one-piece, monolithic hollow plunger body" that includes a body portion, a fishing neck, and a valve cage portion '189 Patent, claim 1 This design aims to improve the structural integrity and reliability of the plunger by forming these key sections as a single unit, addressing weaknesses in prior art multi-component designs '189 Patent, col. 1:21-2:24
  • Asserted Claims: Independent claims 1 and 11, and dependent claims 2-10 and 12-20 Compl. ¶46 Compl. ¶128
  • Accused Features: The complaint alleges the "Liberty Lift Dart Plunger" infringes by having a single, one-piece monolithic metal body that incorporates the fishing neck, body, and valve cage portions Compl. ¶78 Compl. ¶88

U.S. Patent No. 11,293,267 - "Apparatuses And Methods For Scraping"

  • Patent Identification: U.S. Patent No. 11,293,267, "Apparatuses And Methods For Scraping," issued April 5, 2022 Compl. ¶47
  • Technology Synopsis: The patent describes a plunger lift apparatus with "at least one scraping feature formed integrally with the outer surface" '267 Patent, claim 1 This feature comprises a plurality of ridges and grooves designed to scrape material like paraffin and scale from the inner surface of well tubing as the plunger travels through it, preventing buildup that can impede operation '267 Patent, abstract '267 Patent, col. 2:40-50
  • Asserted Claims: Independent apparatus claim 1 and independent method claim 12, along with their respective dependent claims (Compl. ¶¶ 54-56; Compl. ¶¶136-137).
  • Accused Features: The "Liberty Lift Diamond Plunger" is alleged to infringe with its scraping features, described as being machined directly into the plunger body in a diamond pattern of ridges and grooves Compl. ¶92 Compl. ¶97 The complaint includes a photograph of the accused Diamond Plunger showing these features Compl. ¶94

U.S. Patent No. 10,221,849 - "Forged Flange Lubricator"

  • Patent Identification: U.S. Patent No. 10,221,849, "Forged Flange Lubricator," issued March 5, 2019 Compl. ¶56
  • Technology Synopsis: The patent describes a wellhead lubricator where the "main body, the first non-threaded flange, and the second non-threaded flange are a unitary structure devoid of applied junctions" '849 Patent, claim 1 Forming the body and flanges from a single forged piece eliminates welded junctions, which are identified as common points of failure in conventional lubricators due to high pressures and vibrations '849 Patent, col. 1:60-65
  • Asserted Claims: Independent claims 1 and 13, and their respective dependent claims Compl. ¶64 Compl. ¶¶146-147
  • Accused Features: The "Liberty Lift Lubricator" is alleged to infringe by having its main body, wellhead flange, and side outlet flanges formed from a single piece of metal, constituting a unitary structure Compl. ¶99 Compl. ¶104 Compl. ¶110

U.S. Patent No. 10,718,327 - "Forged Flange Lubricator"

  • Patent Identification: U.S. Patent No. 10,718,327, "Forged Flange Lubricator," issued July 21, 2020 Compl. ¶65
  • Technology Synopsis: Similar to the '849 Patent, this patent claims a lubricator apparatus where the main body and multiple flanges "are a unitary structure devoid of applied junctions" '327 Patent, claim 1 The innovation is aimed at improving durability by creating these components as a single, integrated unit, avoiding weaker "applied junctions" like welds '327 Patent, col. 1:55-2:8
  • Asserted Claims: Independent claims 1 and 13, and their respective dependent claims Compl. ¶73 Compl. ¶¶134-135
  • Accused Features: The "Liberty Lift Lubricator" is accused of infringing by being a unitary structure where the main body and flanges are formed from a single piece of material Compl. ¶99 Compl. ¶104 Compl. ¶110 A photograph provided in the complaint shows the allegedly infringing lubricator, highlighting its single-piece construction Compl. ¶100

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are the "Liberty Lift Dart Plunger," "Liberty Lift Diamond Plunger," and "Liberty Lift Lubricator" (collectively, the "Accused Products") Compl. ¶17

Functionality and Market Context

  • The complaint alleges the Accused Products are components of plunger lift systems used in oil and gas wells Compl. ¶14 Compl. ¶21 The Dart Plunger is described as a bypass plunger with a "single, one-piece, monolithic piece of metal" body containing a dart valve and clutch mechanism Compl. ¶78 The Diamond Plunger is described as having a "unitary body construction" with integral "scraping features" arranged in a diamond pattern of ridges and grooves to remove paraffin and scale from well tubing Compl. ¶89 Compl. ¶92 The Liberty Lift Lubricator is described as a wellhead component where the "main body, the wellhead flange, and the side outlet flanges are formed from a single piece of metal" Compl. ¶99
  • The complaint asserts that each of the Accused Products replicates a corresponding patented Flowco product and that they are marketed in direct competition, primarily based on price Compl. ¶23 The complaint includes a photograph of the accused Dart Plunger, showing its one-piece body and internal components Compl. ¶84

IV. Analysis of Infringement Allegations

The provided patent documents did not include the full specification for U.S. Patent Nos. 9,957,785 and 9,915,133. Therefore, column and line citations for the claim elements, as required by the patent citation format, cannot be provided in the following charts.

'785 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a hollow plunger body and valve cage formed as one integrated piece having first and second ends, the valve cage for enclosing a dart valve and a split bobbin clutch assembly formed at the second end thereof and having first threads at the distal end thereof for receiving a retaining device for retaining the dart valve... The Dart Plunger is described as having a hollow plunger body where the fishing neck, body portion, and valve cage portion are "formed as a single, one-piece, monolithic piece of metal." The valve cage is alleged to be formed integrally with the plunger body. ¶78 Not provided
a partition nut the partition nut adjustably spacing the dart valve and the split bobbin clutch assembly within the valve cage The Dart Plunger is alleged to include a partition nut that "locates the clutch in position within the valve cage, and adjustably spaces the dart valve from the clutch." ¶82 Not provided
the dart valve having a valve head connected to a valve stem, the dart valve reciprocatingly disposed within the valve cage such that the valve head is oriented toward a valve seat formed within the hollow body The Dart Plunger is alleged to include a dart valve with a valve head connected to a valve stem. The dart valve is alleged to reciprocate between an open position and a closed position where it seats against a valve seat in the hollow body. ¶80 Not provided
the retaining device having second threads formed on the outer surface of one end for threading the retaining device into the first threads of the valve case The Dart Plunger is alleged to have a retaining nut with external threads that is threaded into the distal end of the valve cage to retain the dart valve and clutch. ¶83 Not provided
  • Identified Points of Contention:
    • Scope Questions: A potential issue may be whether the accused Dart Plunger's components, such as the "split bobbin clutch" and "partition nut," meet the specific structural and functional requirements of those terms as defined or implied within the '785 Patent.
    • Technical Questions: The infringement analysis may focus on whether the accused "tensioning member" of the clutch, described as an elastomeric ring, falls within the scope of the claimed "split bobbin clutch assembly," which may raise questions of literal infringement versus the doctrine of equivalents Compl. ¶81

'133 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a unitary hollow plunger body and valve cage formed in one integrated piece... The Dart Plunger is described as a bypass plunger with a hollow plunger body and integrally formed valve cage, all made from a "single, one-piece, monolithic piece of metal." ¶78 Not provided
a poppet valve having a valve head connected to a downward-extending valve stem, the poppet valve reciprocatingly disposed within the valve cage such that the valve head is oriented toward a valve seat formed within the hollow plunger body The Dart Plunger is alleged to include a dart (poppet) valve with a head connected to a stem, which reciprocates to seat against a valve seat within the plunger body. ¶80 Not provided
a partition nut having external threads...wherein the partition nut is disposed on the valve stem within the valve cage for locating a clutch... The Dart Plunger is alleged to have a partition nut with external threads that engages internal threads in the valve cage and is disposed on the valve stem to locate the clutch. ¶82 Not provided
the clutch is disposed within the valve cage and formed of a split bobbin having cylindrical bobbin halves secured around the valve stem by at least one garter spring surrounding the split bobbin The complaint alleges the Dart Plunger includes a clutch with a split bobbin. However, it states the bobbin halves are secured by an "elastomeric ring" that performs the same function as a "garter spring." ¶81 Not provided
the retaining nut having external threads...to retain the poppet valve and the clutch within the valve cage. The Dart Plunger is alleged to use a retaining nut with external threads that threads into the valve cage to retain the internal components. ¶83 Not provided
  • Identified Points of Contention:
    • Equivalents Questions: The complaint explicitly alleges that the accused product's "elastomeric ring" performs the same function, in the same way, to achieve the same result as the claimed "garter spring" Compl. ¶81 This suggests an argument under the doctrine of equivalents is anticipated, which will be a central point of contention, as the defendant may argue this is a distinct, non-infringing design.
    • Technical Questions: A factual question will be whether the combination of the accused "split bobbin" and "elastomeric ring" constitutes the claimed "clutch...formed of a split bobbin...secured...by at least one garter spring," raising a potential dispute over both literal infringement and equivalence.

V. Key Claim Terms for Construction

  • The Term: "one integrated piece" (from '785 Patent) / "unitary" (from '133, '189, '849, '327 Patents)

  • Context and Importance: This concept is foundational to five of the six asserted patents and central to the infringement allegations against all three accused product types. The dispute will likely focus on whether the accused products, alleged to be made from a "single piece of metal," meet the patents' requirements for being a "unitary structure devoid of applied junctions" Compl. ¶104 Compl. ¶105 Practitioners may focus on this term because it is the core of the asserted technological improvement over prior art that used welded or bolted components.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The patents may describe the unitary body as being formed by processes like forging or machining, which could be argued to cover a range of single-piece manufacturing methods Compl. ¶105 For example, the specification of the '849 Patent states the claims do not require any particular method of manufacture '849 Patent, col. 6:41-48
    • Evidence for a Narrower Interpretation: The patents define an "applied junction" as a "union of separate components applied together by a secondary process," such as welding or bolting '849 Patent, col. 3:32-39 Compl. ¶105 This explicit contrast could be used to argue that any manufacturing process involving the joining of previously separate parts, even if not a traditional weld, falls outside the scope of "unitary."

  • The Term: "garter spring" (from '133 Patent)

  • Context and Importance: The infringement allegation for the '133 Patent hinges on this term. The complaint alleges the accused Dart Plunger uses an "elastomeric ring" as an equivalent to the claimed "garter spring" Compl. ¶81 The construction of this term will determine whether infringement must be proven under the doctrine of equivalents, which carries a higher burden for the plaintiff.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The complaint does not provide the patent specification for the '133 Patent. A plaintiff might argue that the term should be given its plain and ordinary meaning within the context of the patent, which could encompass any annular spring member that provides a radially inward force, including an elastomeric one.
    • Evidence for a Narrower Interpretation: A defendant would likely argue that a "garter spring" has a specific structural meaning in the mechanical arts: a helically coiled spring connected end-to-end to form a circle. They would argue this structure is distinct from a solid "elastomeric ring," and that the claim is therefore not literally infringed.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges active inducement of infringement for all six patents-in-suit. The allegations are based on Defendant's alleged actions of instructing customers on installation and operation, providing field personnel to install and service the products, and marketing the products for infringing uses Compl. ¶113 Compl. ¶121 Compl. ¶129 Compl. ¶138 Contributory infringement is also alleged for the method claim of the '267 Patent and system claims of the '849 and '327 Patents, asserting the accused products are material parts of the claimed inventions not suitable for substantial non-infringing use Compl. ¶139 Compl. ¶149 Compl. ¶137
  • Willful Infringement: Willfulness is alleged for all patents. The allegations are based on Defendant's alleged actual knowledge of the patents and infringement contentions since at least September 2024, when Plaintiff sent a notice letter, and again in August 2025, when Plaintiff provided claim charts (Compl. ¶¶ 24-26). The complaint alleges that Defendant continued to infringe for more than two years with this knowledge and after the original complaint was filed, constituting willful, deliberate, and knowing disregard of Plaintiff's rights Compl. ¶114 Compl. ¶122

VII. Analyst’s Conclusion: Key Questions for the Case

  • A core issue will be one of technical equivalence: does the accused Dart Plunger’s "elastomeric ring" clutch mechanism perform substantially the same function in substantially the same way to achieve substantially the same result as the "garter spring" explicitly recited in claim 1 of the '133 Patent? The complaint’s own language frames this as a central point of contention.
  • A second key question will be one of definitional scope: how will the court construe the term "unitary structure devoid of applied junctions," which appears across multiple patents? The outcome will depend on whether the accused products, allegedly formed from a "single piece of metal," are found to meet this limitation, or if their manufacturing process is found to create what could be considered an "applied junction."
  • A third issue will be one of evidentiary proof for method claims: for the asserted method claim 12 of the '267 Patent, a key question for the court will be whether Plaintiff can produce sufficient evidence that Defendant, its personnel, or its customers, performed all the required steps of the claimed method, including "releasing a plunger within the tubular body" and "scraping material from an inner surface."