Perma Liner Industries LLC v. NuFlow Tech USA Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Perma-Liner Industries, LLC (Delaware)
  • Defendant: NuFlow Technologies U.S.A., Inc. (Delaware)
  • Plaintiff’s Counsel: Morris, Nichols, Arsht & Tunnell LLP; Goodwin Procter LLP
• Case Identification: 1:24-cv-00721, D. Del., 06/18/2024
• Venue Allegations: Venue is alleged to be proper in the District of Delaware because the Defendant is a Delaware corporation and therefore resides in the district.
• Core Dispute: Plaintiff alleges that Defendant’s NuCure Cold Cure UV pipe repair systems and methods infringe three patents related to trenchless conduit lining technology using light-curable resins.
• Technical Context: The technology concerns trenchless pipe rehabilitation, where a resin-impregnated fabric liner is cured in place by an internal, portable light source, offering a faster and more site-flexible alternative to traditional excavation or heat-based curing methods.
• Key Procedural History: Plaintiff alleges providing Defendant with pre-suit notice of infringement. A letter was sent on November 17, 2023, identifying the ’628 and ’647 patents and including claim charts. A second letter on May 30, 2024, reiterated the infringement allegations and attached the then-allowed claims of the ’458 patent. These events form the basis for the willfulness allegations.

Case Timeline

Date	Event
2017-08-18	Patent Priority Date ('628, '647, '458 Patents)
2023-06-13	'628 Patent Issue Date
2023-10-31	'647 Patent Issue Date
2023-11-17	Pre-Suit Notice Letter ('628 & '647 Patents)
2024-05-30	Pre-Suit Notice Letter ('458 Patent allowed claims)
2024-06-18	'458 Patent Issue Date
2024-06-18	Complaint Filing Date

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

U.S. Patent No. 11,674,628 - "Method, Apparatus and System for Lining Conduits"

• Patent Identification: U.S. Patent No. 11,674,628, issued June 13, 2023.

The Invention Explained

• Problem Addressed: The patent describes drawbacks with prior art pipe lining methods, particularly those using thermally cured resins, which require costly refrigeration during transport and are vulnerable to on-site temperature variations, such as cold groundwater, that can lead to incomplete curing and blockages (’628 Patent, col. 5:35-6:12).
• The Patented Solution: The invention is an apparatus for lining conduits using a light-curable resin, which avoids thermal sensitivity issues (’628 Patent, col. 6:53-7:12). The system places a flexible light activator (e.g., an LED array) inside a translucent, inflatable bladder. This assembly is positioned inside a resin-impregnated liner and inserted into the pipe. The bladder expands to press the liner against the pipe wall, and the light activator cures the resin. A key aspect is that the light activator is configured to receive power at more than one location along its length, which aims to improve the consistency and speed of the cure (’628 Patent, col. 22:64-66; Fig. 10).
• Technical Importance: By using light-curing and a distributed power configuration, the technology seeks to make trenchless pipe repair faster, more reliable, and less dependent on external environmental conditions compared to prior methods (’628 Patent, col. 6:53-7:12).

Key Claims at a Glance

• The complaint asserts at least independent claim 33 (Compl. ¶28).
• Essential elements of Claim 33 (Apparatus):
  • A pipe rehabilitation packer having a bladder configured to expand toward the conduit wall, wherein the bladder is translucent, tubular, and flexible;
  • A light curing activator positioned within the bladder; and
  • The light curing activator has a length and is configured to receive power at more than one location along the length.

U.S. Patent No. 11,802,647 - "Method, Apparatus and System for Lining Conduits"

• Patent Identification: U.S. Patent No. 11,802,647, issued October 31, 2023.

The Invention Explained

• Problem Addressed: The patent addresses the same problems as the ’628 Patent, namely the high costs, logistical challenges, and unreliability of traditional thermal-curing pipe lining systems (’647 Patent, col. 5:38-6:15).
• The Patented Solution: This patent discloses an apparatus with a more specific light activator structure. The activator features multiple light source strips wrapped in a "spiral configuration" around a flexible central member (’647 Patent, Abstract). The apparatus is explicitly described as having a "first portion" and a "second portion," with wiring to provide power to the light strips in both portions. This entire assembly, including the bladder, is designed to be pushed or pulled into the conduit to be repaired (’647 Patent, col. 20:30-46; Fig. 5).
• Technical Importance: The claimed spiral configuration of light strips is intended to provide more uniform 360-degree light exposure to the resin liner, which could be particularly advantageous for ensuring a complete cure in non-linear pipe sections or in pipes with varying internal diameters (’647 Patent, col. 9:35-43).

Key Claims at a Glance

• The complaint asserts at least independent claim 1 (Compl. ¶36).
• Essential elements of Claim 1 (Apparatus):
  • A bladder that is translucent, flexible, and configured to expand outward;
  • A light activator positioned within the bladder, which has a first portion, a second portion, and multiple light source strips wrapped around a flexible member in a spiral configuration;
  • The light activator is wired to provide power to the light strip at the first portion and the light strip at the second portion; and
  • The bladder and light activator are configured to be pushed or pulled into the hollow conduit.
• The complaint reserves the right to assert dependent claims 2–6, 9, 12–13, 15–17, 19–21, and 23–25 (Compl. ¶36).

U.S. Patent No. 12,014,458 - "Method, Apparatus and System for Lining Conduits"

• Patent Identification: U.S. Patent No. 12,014,458, issued June 18, 2024.
• Technology Synopsis: This patent claims a method of pipe repair utilizing an apparatus similar to that described in the ’647 Patent. The claimed method comprises the steps of taking a bladder with an internal light activator (having spirally-wrapped light strips and separate wiring connections), impregnating a liner with light-activated resin, forming a repair assembly, operatively attaching a power hose, pushing or pulling the assembly into the conduit, expanding the bladder with fluid pressure, and activating the first and second light strips to initiate curing (’458 Patent, col. 19:47-21:2).
• Asserted Claims: At least independent claim 1 and dependent claims 2-5, 7, 10-13, 16, 18, and 19 (Compl. ¶44).
• Accused Features: The complaint alleges that the use of the NuCure Cold Cure UV product, particularly as instructed by Defendant through training and promotional materials, constitutes performance of the claimed method steps (Compl. ¶44-45).

III. The Accused Instrumentality

• Product Identification: The NuCure Cold Cure UV product (Compl. ¶26).
• Functionality and Market Context:
  • The complaint describes the accused product as an apparatus for repairing pipes that includes a liner impregnated with a UV curable resin, a translucent and expandable bladder, and "multiple strings of LED ultraviolet lights" contained within the bladder (Compl. ¶26). In operation, the product is inserted into a conduit, the bladder is expanded to press the liner against the conduit wall, and the LED lights are activated to cure the resin (Compl. ¶26). The complaint references a YouTube video allegedly demonstrating the components and use of the NuCure Cold Cure UV product (Compl. ¶26, 29).
  • The complaint alleges that Plaintiff and Defendant are direct competitors in an "emerging market where technology is a key differentiator," suggesting the commercial importance of these light-curing systems (Compl. ¶33).

IV. Analysis of Infringement Allegations

The complaint references claim chart exhibits that were not provided. The following is a summary of the narrative infringement theories presented in the complaint.

'628 Patent Infringement Allegations

The complaint alleges that the NuCure Cold Cure UV product directly infringes at least claim 33 of the ’628 Patent (Compl. ¶28). The infringement theory maps features of the accused product to the elements of claim 33. Specifically, the complaint alleges the NuCure product is an apparatus for repairing a conduit that includes a "pipe rehabilitation packer having a bladder" that is "translucent, tubular, and flexible," and a "light curing activator positioned within the bladder" (Compl. ¶28; ’628 Patent, col. 22:60-63). The core of the allegation is that this light curing activator "has a length and is configured to receive power at more than one location along the length," thereby meeting the final limitation of the asserted claim (Compl. ¶28; ’628 Patent, col. 22:64-66).

'647 Patent Infringement Allegations

For the ’647 Patent, the complaint alleges direct infringement of multiple claims, including independent claim 1, by the NuCure Cold Cure UV product (Compl. ¶36). The allegations track the elements of claim 1, asserting that the product is an apparatus comprising a "translucent, flexible" bladder and an internal light activator (Compl. ¶36; ’647 Patent, col. 20:30-34). The complaint alleges the accused light activator has a "first portion, a light activator second portion, and multiple light source strips wrapped around a flexible member in a spiral configuration" and is "wired to provide power to the first light strip...and the second light strip" (Compl. ¶36; ’647 Patent, col. 20:35-43). The complaint further alleges the apparatus is "configured to be pushed or pulled into the hollow conduit" (Compl. ¶36; ’647 Patent, col. 20:44-46).

Identified Points of Contention:

• Technical Questions: A primary factual question will be whether the "multiple strings of LED" in the accused product (Compl. ¶26) are arranged in the "spiral configuration" required by the ’647 Patent. Likewise, evidence will be required to determine if the accused product's activator is "configured to receive power at more than one location" (’628 Patent) and is specifically "wired to provide power to the first light strip ... and the second light strip" (’647 Patent) as claimed.
• Scope Questions: The case may raise the question of whether the general description of "multiple strings of LED" in the complaint is sufficient to meet the more specific structural and electrical configurations recited in the asserted claims, or if there is a fundamental mismatch that discovery will reveal.

V. Key Claim Terms for Construction

• The Term: "configured to receive power at more than one location along the length" (from '628 Patent, Claim 33)

• Context and Importance: This term is central to the infringement analysis of the ’628 Patent. Its construction will determine what electrical architecture satisfies the claim. Practitioners may focus on this term because the dispute will likely center on whether the accused product's power delivery system, whatever its design, meets this functional requirement.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification discloses a "two way continuous power circuit" (’628 Patent, col. 21:51-52), which could suggest that a single power input that is internally distributed to multiple points along the activator's length would fall within the claim's scope.
  • Evidence for a Narrower Interpretation: The phrase "receive power at more than one location" could be argued to require multiple distinct, physical points where power enters the activator from an external source. Figure 10, showing wiring to "both ends," could be used to support an interpretation requiring physically separate power entry points (’628 Patent, Fig. 10).

• The Term: "multiple light source strips wrapped around a flexible member in a spiral configuration" (from '647 Patent, Claim 1)

• Context and Importance: This structural limitation is a key point of novelty for the ’647 Patent. Infringement will depend on whether the physical arrangement of the LEDs in the accused product can be characterized as a "spiral configuration."

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: A party might argue that "spiral configuration" does not require a perfect, uniform helix and could encompass any generally winding or twisted arrangement of light strips around the central member.
  • Evidence for a Narrower Interpretation: The patent's figures, particularly Figure 5, depict a distinct and regular spiral wrapping (’647 Patent, Fig. 5). A party could argue these embodiments limit the claim term to a structured, repeating spiral, potentially excluding less orderly arrangements.

VI. Other Allegations

• Indirect Infringement: The complaint alleges both induced and contributory infringement for all three patents. Inducement is based on allegations that Defendant instructs customers on how to use the NuCure product in an infringing manner through training, user information, and a YouTube video (Compl. ¶29, 37, 45). Contributory infringement is based on allegations that Defendant supplies key components (e.g., "UV light strands, translucent bladders") that are especially adapted for infringement and have no substantial non-infringing use (Compl. ¶30, 38, 46).
• Willful Infringement: Willfulness is alleged for all patents. The claim is primarily based on alleged pre-suit knowledge from cease-and-desist letters sent on November 17, 2023 and May 30, 2024 (Compl. ¶31, 34, 39, 42). For the ’458 Patent, which issued on the date of filing, the complaint alleges notice "since at least as early the filing of this Complaint" (Compl. ¶47) but also notes that its allowed claims were provided in the May 30 letter, supporting a pre-suit knowledge allegation (Compl. ¶25, 50).

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

• A central issue will be one of structural correspondence: Does the physical arrangement of the Defendant's "multiple strings of LED" meet the specific "spiral configuration" required by the ’647 patent, or is there a material difference in the product's actual construction?
• A key evidentiary question will be one of electrical architecture: What is the precise wiring and power delivery mechanism of the accused light activator? Evidence from discovery will be needed to determine if it is "configured to receive power at more than one location" (’628 Patent) and provides power to distinct "first" and "second" portions (’647 Patent) as claimed.
• Regarding the ’458 method patent, a primary focus may be on proving direct infringement: Can the Plaintiff establish that a single actor performs all steps of the claimed method, or alternatively, demonstrate that the Defendant's instructions and control over its customers are sufficient to hold it responsible for their performance of the method?