DCT
4:25-cv-05175
Straight Line v. Insultherm
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Straight Line Industrial Services, Inc. (Texas)
- Defendant: Insultherm Inc. (Texas)
- Plaintiff’s Counsel: EDMONDS & CMAIDALKA, P.C.
- Case Identification: 4:25-cv-05175, S.D. Tex., 10/29/2025
- Venue Allegations: Venue is alleged to be proper based on the Defendant's principal place of business in the district and because a substantial part of the events giving rise to the claims, including the direction of patent enforcement threats, occurred there.
- Core Dispute: Plaintiff seeks a declaratory judgment that its proposed industrial insulation panels do not infringe Defendant's patents, alleging that Defendant misappropriated Plaintiff's confidential bid to a mutual customer and then issued baseless infringement threats to interfere with the business relationship.
- Technical Context: The technology concerns specialized thermal insulation systems for large industrial pressure vessels, such as coke drums used in petroleum refineries, which require robust designs to accommodate extreme temperatures and thermal expansion.
- Key Procedural History: The complaint alleges that one day after Plaintiff submitted a confidential bid to a customer, Defendant, having obtained a copy of the bid, sent Plaintiff a cease-and-desist letter alleging patent infringement. This event prompted Plaintiff to file the current action for declaratory judgment of non-infringement and other commercial torts.
Case Timeline
| Date | Event |
|---|---|
| 2016-04-26 | Priority Date for ’190 and ’890 Patents |
| 2019-06-18 | U.S. Patent No. 10,323,190 Issues |
| 2021-06-15 | U.S. Patent No. 11,034,890 Issues |
| 2025-10-20 | Plaintiff SLIS submits confidential bid proposal to Marathon |
| 2025-10-21 | Defendant Insultherm sends cease-and-desist letter to SLIS |
| 2025-10-29 | Complaint for Declaratory Judgment filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 10,323,190 - "Insulated Coke Drum, Insulation System Therefore, and Method of Installing Same"
The Invention Explained
- Problem Addressed: The patent's background describes how conventional insulation on coke drums can deteriorate due to the vessel's significant thermal expansion and contraction, allowing water to penetrate and reduce thermal efficiency, which can negatively impact the petroleum coking process (U.S. Patent No. 10,323,190, col. 1:50-59).
- The Patented Solution: The invention is an insulation system designed to "float" off the surface of the coke drum. This is achieved by welding support members (or "clips") to the drum, which hold, but are not attached to, a series of support rings. This arrangement creates a gap that allows the drum to move thermally without damaging the insulation. Insulation panels are then secured to these rings and are connected to each other with standing seams, while external tensioned cables provide overall structural integrity ('190 Patent, Abstract; col. 2:16-28).
- Technical Importance: This design seeks to provide a durable, weather-proof, and more easily maintained insulation system that can withstand the severe operational stresses of coke drums, thereby improving the vessel's long-term performance and reliability ('190 Patent, col. 2:2-9).
Key Claims at a Glance
- The complaint notes that Defendant's cease-and-desist letter identified claims 1, 2, 4, 7, 9, 14, 16 and 20 (Compl. ¶16). Independent claim 1 is representative of the asserted system.
- Essential elements of Independent Claim 1 include:
- A coke drum with an exterior surface.
- An insulation system installed on the exterior surface comprising:
- An insulation support system with weldments fixed to the drum and vertically spaced insulation support rings that are "supported by but not attached to the weldments."
- A plurality of insulation panels secured to the support rings, featuring an exterior metal jacket and "single-folded standing seams."
- A plurality of "external tensioned insulation securing cables" routed through eyelets in the standing seams "external of the insulation panels."
- The complaint seeks a declaration of non-infringement as to all claims of the patent (Compl. ¶66).
U.S. Patent No. 11,034,890 - "Insulated Vessels, Insulation Systems Therefore, and Methods of Installing Same"
- Patent Identification: U.S. Patent No. 11,034,890, "Insulated Vessels, Insulation Systems Therefore, and Methods of Installing Same," issued June 15, 2021.
- Technology Synopsis: As a divisional of the application leading to the ’190 Patent, this patent describes methods for installing similar thermal insulation systems on industrial vessels. The methods focus on attaching a "floating" support structure that accommodates thermal expansion, attaching insulation panels with standing seams, and securing the assembly with externally routed tensioning cables (U.S. Patent No. 11,034,890, Abstract).
- Asserted Claims: The complaint seeks a general declaration of non-infringement (Compl. ¶64). The independent claims of the patent are method claims 1 and 3 ('890 Patent, col. 19:54, col. 20:26).
- Accused Features: The complaint identifies Plaintiff's "proposed insulated panels" as the subject of the non-infringement controversy but does not provide specific technical details about the panels or the proposed installation method (Compl. ¶11, ¶64).
III. The Accused Instrumentality
Product Identification
- Plaintiff's "proposed insulated panels" offered for the replacement of external thermal insulation on a coke drum at a Marathon refinery (Compl. ¶11, ¶16).
Functionality and Market Context
- The complaint alleges that Plaintiff's bid proposal was limited to the "replacement of insulated panels only and did not include the installation of additional systems or components beyond the replacement panels" (Compl. ¶11). This statement suggests that Plaintiff's offering may not include the support structure (weldments and rings) described in the patents-in-suit. No other technical details about the construction or function of the panels are provided.
- The complaint frames the dispute as arising from a competitive bidding process where Plaintiff and Defendant are direct competitors in the market for industrial insulation solutions (Compl. ¶10).
IV. Analysis of Infringement Allegations
No probative visual evidence provided in complaint.
Because this is a declaratory judgment action for non-infringement, the following chart summarizes Plaintiff's asserted basis for not infringing the representative system claim of the '190 Patent.
10,323,190 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| (a) a coke drum having an external diameter, an exterior surface, and a longitudinal axis | The complaint alleges Plaintiff's proposal was for insulated panels only, not for a coke drum itself. | ¶11 | col. 19:56-58 |
| (b) i) an insulation support system comprising a series of spaced apart weldments welded to the coke drum exterior surface... and a plurality of vertically spaced insulation support rings supported by but not attached to the weldments... | The complaint alleges Plaintiff's proposal "did not include the installation of additional systems or components beyond the replacement panels," suggesting it does not supply this support system. | ¶11 | col. 20:1-8 |
| (b) ii) a plurality of insulation panels secured to the support rings, each insulation panel comprising insulation material and an exterior metal jacket, each insulation panel positioned between horizontally adjacent insulation panels with single-folded standing seams | Plaintiff's offering includes "insulated panels." The complaint provides no detail regarding how they are secured or whether they have single-folded standing seams. | ¶11 | col. 20:9-14 |
| (b) iii) a plurality of external tensioned insulation securing cables corresponding in number to the plurality of support rings, each of the cables routed through respective horizontally aligned eyelets in each single-folded standing seam external of the insulation panels | The complaint does not provide sufficient detail for analysis of this element. | ¶11 | col. 20:15-20 |
Identified Points of Contention
- Scope Questions: A central dispute may be whether supplying only "replacement insulated panels," without the claimed coke drum or the specific "insulation support system," can constitute direct infringement of the system claimed in the ’190 Patent. The complaint's framing suggests a theory that Plaintiff is a mere component supplier (Compl. ¶11).
- Technical Questions: The complaint provides no technical information about the accused panels. A key factual question for the court will be how Plaintiff's panels are constructed and how they are intended to be installed. Specifically, are they designed for use with the patented "floating" support system, or are they compatible with other, non-infringing mounting systems?
V. Key Claim Terms for Construction
The Term: "insulation support system"
- Context and Importance: Plaintiff alleges it only provides "insulated panels" and not "additional systems or components" (Compl. ¶11). The definition of "insulation support system" will be critical to determining if Plaintiff's product, as described, meets the limitations of the claims. Practitioners may focus on this term to distinguish the panels themselves from the underlying structure to which they attach.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent claims an overall "insulation system" in element (b), which is then broken down into sub-parts: the "insulation support system" (i), the "insulation panels" (ii), and the "securing cables" (iii) ('190 Patent, col. 20:1-20). This structure suggests the "insulation support system" is a distinct sub-component comprising the weldments and rings, separate from the panels.
- Evidence for a Narrower Interpretation: The term is explicitly defined by its constituent parts in claim 1(b)(i) as "comprising a series of spaced apart weldments... and a plurality of... insulation support rings" ('190 Patent, col. 20:2-8). This definition is self-contained within the claim and appears to clearly exclude the insulation panels themselves.
The Term: "supported by but not attached to the weldments"
- Context and Importance: This phrase describes the core "floating" concept of the invention, which allows for thermal movement. Whether Plaintiff's panels are intended for use with a system having this specific functional relationship will be central to any indirect infringement analysis.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: Language in the summary and detailed description emphasizes the functional benefit of allowing the drum to move "without damaging the insulation" ('190 Patent, col. 2:19-20). This could support a construction that covers any physical arrangement achieving this unattached, supportive function.
- Evidence for a Narrower Interpretation: Specific embodiments in the patent illustrate this relationship with a distinct physical structure: a horizontal ring (17) resting within a slot (48) formed in the weldment (18), which allows it to "float" ('190 Patent, Fig. 3; col. 10:49-52). A party could argue the claim term should be limited to this or a structurally similar arrangement.
VI. Other Allegations
- Indirect Infringement: The complaint seeks a broad declaration of non-infringement, which would cover theories of both direct and indirect infringement (Compl. ¶66). However, the complaint pleads no facts regarding Defendant's potential allegations of inducement or contributory infringement, such as knowledge or intent. The core of Plaintiff's pleading is that it does not provide the complete patented system, a defense against direct infringement.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of infringement scope: can the act of supplying only "replacement insulated panels," as Plaintiff alleges its bid offered, constitute direct infringement of system claims that recite a coke drum and a specific, multi-part support structure to which the panels are attached?
- A key evidentiary question will be one of technical implementation: given the lack of detail in the complaint, discovery will need to establish the actual design of Plaintiff's panels and their intended installation method. This will determine if the panels are designed for use with the patented "floating" support system, which would be central to any analysis of indirect infringement, or if they are intended for a distinct, non-infringing application.