Flowco Productions LLC v. Liberty Lift Solutions LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Flowco Productions LLC (Texas)
  • Defendant: Liberty Lift Solutions LLC (Texas)
  • Plaintiff's Counsel: Fisherbroyles, LLP
• Case Identification: 4:26-cv-05523, S.D. Tex., 07/13/2026
• Venue Allegations: Plaintiff alleges venue is proper because Defendant is a Texas company that resides in the Southern District of Texas and has a regular and established place of business in the district.
• Core Dispute: Plaintiff alleges that Defendant's "Dart" and "Diamond" plunger lift products, used in the oil and gas industry, infringe four U.S. patents related to the design, construction, and functionality of bypass plungers.
• Technical Context: The technology involves plunger lift systems, which are mechanical pistons used in oil and gas wells to remove liquid accumulation from the wellbore, thereby maintaining pressure and maximizing production.
• Key Procedural History: The complaint alleges that Defendant had actual knowledge of the patents-in-suit at least as of September 5, 2024, when Plaintiff sent Defendant a cease and desist letter. It also alleges constructive notice based on Plaintiff's virtual patent marking practices.

Case Timeline

Date	Event
2015-02-20	Earliest Priority Date ('785, '133, '189 Patents)
2018-03-13	U.S. Patent No. 9,915,133 Issues
2018-05-01	U.S. Patent No. 9,957,785 Issues
2018-11-30	Earliest Priority Date ('267 Patent)
2021-08-31	U.S. Patent No. 11,105,189 Issues
2022-04-05	U.S. Patent No. 11,293,267 Issues
2024-09-05	Plaintiff sends cease and desist letter to Defendant
2026-07-13	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. 9957785, "Unitary Body Bypass Plunger And Valve Cage," issued May 1, 2018 Compl. ¶20

The Invention Explained

• Problem Addressed: The patent family addresses the complexity and reliability problems of conventional bypass plungers, which are subjected to high impact forces, caustic fluids, and elevated temperatures in downhole environments '133 Patent, col. 2:15-20 Prior art clutch mechanisms, in particular, could be prone to failure '133 Patent, col. 2:8-14
• The Patented Solution: The invention proposes a bypass plunger with a "hollow plunger body and valve cage formed as one integrated piece" '785 Patent, claim 1 This "unibody" design reduces the number of components and threaded joints, which are potential points of failure, thereby simplifying construction and improving durability '133 Patent, col. 5:17-24 The '785 Patent specifically claims a configuration using a "partition nut" to adjustably space a "dart valve" and a "split bobbin clutch assembly" within the unitary valve cage '785 Patent, claim 1
• Technical Importance: By creating a more robust, simplified plunger design, the invention aimed to increase operational reliability and longevity in the demanding conditions of oil and gas wells, reducing costly downtime.

Key Claims at a Glance

• The complaint asserts independent claim 1 Compl. ¶27
• The essential elements of independent claim 1 include:
  • a hollow plunger body and valve cage formed as one integrated piece having first and second ends, with the valve cage enclosing a dart valve and a split bobbin clutch assembly;
  • a partition nut for adjustably spacing the dart valve and the split bobbin clutch assembly within the valve cage;
  • a dart valve that reciprocates within the valve cage; and
  • a retaining device for retaining the dart valve.
• The complaint reserves the right to assert dependent claims 2-10 Compl. ¶76

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

• Patent Identification: U.S. Patent No. 9915133, "Unibody Bypass Plunger With Centralized Helix and Crimple Feature," issued March 13, 2018 Compl. ¶29

The Invention Explained

• Problem Addressed: The patent addresses the structural complexity and potential unreliability of conventional multi-part bypass plungers, particularly concerning the clutch mechanisms that control the internal valve's movement '133 Patent, col. 2:1-14
• The Patented Solution: Similar to the '785 Patent, the '133 Patent discloses a "unitary hollow plunger body and valve cage formed in one integrated piece" '133 Patent, claim 1 This patent, however, specifically claims a clutch formed of a "split bobbin" with "cylindrical bobbin halves" secured around the valve stem by a "garter spring". The design aims to create a more reliable and consistently performing clutch compared to prior art alternatives '133 Patent, col. 12:47-54
• Technical Importance: The invention provided a specific mechanical assembly for a plunger clutch intended to offer more uniform tension and greater dependability under the harsh conditions of a wellbore.

Key Claims at a Glance

• The complaint asserts independent claim 1 Compl. ¶36
• The essential elements of independent 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 in position within the valve cage;
  • a clutch formed of a split bobbin with cylindrical bobbin halves secured by at least one garter spring; and
  • a retaining nut to retain the poppet valve and the clutch within the valve cage.
• The complaint reserves the right to assert dependent claims 2-16 Compl. ¶84

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

• Patent Identification: U.S. Patent No. 11105189, "Unibody Bypass Plunger And Valve Cage," issued August 31, 2021 Compl. ¶38
• Technology Synopsis: This patent discloses a bypass plunger constructed from a "one-piece, monolithic hollow plunger body" '189 Patent, claim 1 The invention addresses reliability by simplifying the plunger's structure, focusing on the interface between a reciprocating dart valve and a valve seat within the monolithic body to ensure a proper seal '189 Patent, abstract
• Asserted Claims: Independent claims 1 and 11 are asserted Compl. ¶46
• Accused Features: The complaint alleges that Defendant's "Dart Plunger" infringes based on its "unitary body construction" and its use of internal valve components configured to provide a sealing arrangement Compl. ¶60 Compl. ¶63 Compl. ¶67

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

• Patent Identification: U.S. Patent No. 11293267, "Apparatuses And Methods For Scraping," issued April 5, 2022 Compl. ¶47
• Technology Synopsis: The patent addresses the problem of material buildup (e.g., paraffin) on the inner walls of well tubing, which can impede plunger movement and reduce production '267 Patent, col. 2:40-49 The solution is a plunger apparatus with at least one integrated "scraping feature" on its outer surface, comprising a specific arrangement of ridges and grooves designed to scrape material from the tubing wall '267 Patent, abstract '267 Patent, claim 1
• Asserted Claims: Independent claims 1 and 12 are asserted Compl. ¶55
• Accused Features: The complaint alleges that Defendant's "Diamond Plunger" infringes through its "plurality of scraping features formed by grooves in the sealing features where the grooves are arranged in a diamond pattern" Compl. ¶71 Compl. ¶74

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are the "Liberty Lift Dart Plungers" and "Liberty Lift Diamond Plungers" Compl. ¶16

Functionality and Market Context

The complaint alleges the Accused Products are used for artificial lift in oil and gas wells Compl. ¶57 The "Dart Plunger" is described as having a "unitary body construction," a central flow path with bypass openings, and internal valve components to control fluid flow Compl. ¶¶60-62 The "Diamond Plunger" is also described as having a unitary body and a central flow path, but is specifically alleged to include "a plurality of scraping features formed by grooves in the sealing features where the grooves are arranged in a diamond pattern" Compl. ¶¶68-71 Both products are marketed as providing durability and performance under repeated operating cycles Compl. ¶64 Compl. ¶72

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'785 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A bypass plunger, comprising: a hollow plunger body and valve cage formed as one integrated piece having first and second ends...	The Dart Plunger is alleged to comprise a "unitary body construction" intended to improve durability and operational efficiency.	¶60	col. 5:17-24
...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 alleged to include internal structures configured to support and retain valve components.	¶63	col. 7:35-39
...a partition nut the partition nut adjustably spacing the dart valve and the split bobbin clutch assembly within the valve cage...	The complaint makes a general allegation that the Dart Plunger embodies features and functionality that satisfy each limitation of the asserted claims.	¶67	col. 16:47-52
...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...	The Dart Plunger is alleged to include valve components positioned within a central flow path and configured to selectively permit and restrict fluid flow.	¶62	col. 7:29-34
...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 include internal structures configured to support and retain valve components.	¶63	col. 7:35-39

'133 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A bypass plunger, comprising: a unitary hollow plunger body and valve cage formed in one integrated piece...	The Dart Plunger is alleged to comprise a "unitary body construction."	¶60	col. 7:5-10
...a poppet valve having a valve head connected to a downward-extending valve stem, the poppet valve reciprocatingly disposed within the valve cage...	The Dart Plunger is alleged to include valve components positioned within a central flow path.	¶62	col. 7:37-43
...a partition nut having external threads...wherein the partition nut is disposed on the valve stem within the valve cage for locating a clutch in position within the valve cage...	The complaint makes a general allegation that the Dart Plunger embodies features that satisfy each claim limitation.	¶67	col. 16:26-30
...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...	The complaint makes a general allegation that the Dart Plunger embodies features that satisfy each claim limitation.	¶67	col. 16:32-36
...the retaining nut having external threads...to retain the poppet valve and the clutch within the valve cage.	The Dart Plunger is alleged to include internal structures configured to support and retain valve components.	¶63	col. 7:37-43

Identified Points of Contention

• Factual Sufficiency: The complaint does not specifically identify a "partition nut" or a "split bobbin clutch" in the accused Dart Plunger. Instead, it relies on general descriptions of "valve components" Compl. ¶62 and a blanket assertion that all limitations are met Compl. ¶67 This raises the question of whether the complaint provides sufficient factual matter, accepted as true, to state a plausible claim for relief under the Iqbal/Twombly pleading standard for these specific structural elements.
• Scope Questions: A central issue may be whether the accused product's alleged "unitary body construction" Compl. ¶60 meets the claim limitation "formed as one integrated piece." The analysis may explore whether this term requires a monolithic construction (machined from a single piece of stock) or if it can read on an assembly of components that are permanently joined (e.g., by welding).
• Technical Questions: An evidentiary question will be whether the internal mechanism of the accused Dart Plunger, which is alleged to "selectively permit and restrict fluid flow" Compl. ¶62, functions as the specific "split bobbin clutch assembly" required by the claims of the '785 and '133 patents. The court may need to compare the structure and operation of the accused device's clutch mechanism against the detailed descriptions provided in the patent specifications.

V. Key Claim Terms for Construction

The Term: "formed as one integrated piece" (['785 Patent, claim 1](https://ex:cit:4); ['133 Patent, claim 1](https://ex:cit:10))

• Context and Importance: This term is the foundation of the "unibody" concept central to the patents. The dispute will likely focus on whether this requires the body and cage to be machined from a single, monolithic piece of metal, or if it can cover components manufactured separately and then permanently joined. Practitioners may focus on this term because the accused product is described as having a "unitary body construction" Compl. ¶60, but the precise manufacturing method is not specified.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The plain language "integrated piece" does not explicitly forbid permanent joining methods like welding, which could be argued to result in a functionally integrated part.
  • Evidence for a Narrower Interpretation: The specifications frequently use "unitary" and "one-piece" interchangeably with "integrated," suggesting an intent to describe a single, non-assembled component '133 Patent, col. 5:17-18 The related '189 patent, which claims priority to the same provisional application, uses the term "monolithic" in its independent claim, which may suggest the inventors viewed these concepts as synonymous '189 Patent, claim 1

The Term: "split bobbin clutch assembly" (['785 Patent, claim 1](https://ex:cit:4)) and "clutch ... formed of a split bobbin" (['133 Patent, claim 1](https://ex:cit:10))

• Context and Importance: This is a specific mechanical component recited in the asserted claims. The complaint does not describe the accused product's clutch in any detail, making this a likely point of dispute. The definition of this term will be critical to determining whether the accused product's internal valve-control mechanism infringes.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patents describe the clutch's function as retarding and controlling the motion of the valve stem '133 Patent, col. 1:50-54 A party could argue that any mechanism performing this function in a similar way should be considered within the claim's scope, potentially under the doctrine of equivalents.
  • Evidence for a Narrower Interpretation: The patents provide detailed descriptions of the clutch's structure, including "cylindrical bobbin halves secured around the valve stem by at least one garter spring" '133 Patent, claim 1 and figures illustrating this specific configuration '133 Patent, Fig. 14 '133 Patent, col. 12:47-51 This specificity may support a narrower construction limited to the disclosed embodiment and its structural equivalents.

VI. Other Allegations

Indirect Infringement

The complaint alleges that Defendant induces and contributes to infringement by "actively inducing direct infringement with knowledge" of the patents Compl. ¶77 Compl. ¶85 Compl. ¶93 Compl. ¶101 The factual basis alleged includes Defendant's advertising and marketing of the Accused Products for their intended use in artificial lift operations, which may include instructions on how to use them in an infringing manner Compl. ¶57 Compl. ¶58

Willful Infringement

The complaint alleges deliberate, willful, and knowing infringement for all four patents-in-suit Compl. ¶78 Compl. ¶86 Compl. ¶94 Compl. ¶102 The basis for this allegation is Defendant's alleged pre-suit knowledge of the patents, established at least by a cease and desist letter sent on September 5, 2024 Compl. ¶26 Compl. ¶35 Compl. ¶44 The complaint also asserts constructive notice via Plaintiff's virtual marking Compl. ¶25 Compl. ¶34 Compl. ¶43 Compl. ¶52

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

• A central threshold issue will be one of factual sufficiency: Does the complaint's general description of the accused "Dart Plunger" provide plausible factual support for the presence of specific structural elements like the "partition nut" and "split bobbin clutch" required by the asserted claims, or does it rely on conclusory allegations that may be vulnerable to a motion to dismiss?
• A core substantive issue will be one of definitional scope: Can the term "formed as one integrated piece", which is central to the patents' "unibody" concept, be construed broadly enough to cover assemblies of permanently joined components, or will it be limited to a "monolithic" construction machined from a single piece of material, as suggested by language in the related '189 patent?
• A key evidentiary question will be one of structural infringement: Assuming the complaint survives, does the accused "Dart Plunger's" internal valve-control mechanism contain the specific structures of the claimed "split bobbin clutch assembly", or is there a fundamental mismatch in mechanical design that would place it outside the scope of the claims, either literally or under the doctrine of equivalents?