PTAB

IPR2016-01351

South Tek Systems LLC v. Engineered Corrosion Solutions LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Fire Protection System Having Reduced Corrosion
  • Brief Description: The ’533 patent relates to using nitrogen gas from a nitrogen generator to inhibit corrosion in “preaction” fire protection sprinkler systems. The claimed system includes a vent operable at a preset pressure limit to allow oxygen-containing gas to exit the piping network as it is displaced by nitrogen.

3. Grounds for Unpatentability

Ground 1: Claims 1-2 and 5-10 are obvious over Golinveaux, Applicant Admitted Prior Art (AAPA), and Craig.

  • Prior Art Relied Upon: Golinveaux (Application # 2006/0021759), AAPA (within the ’533 patent specification), and Craig (Patent 6,102,066).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Golinveaux taught a preaction sprinkler system pressurized with nitrogen, including a relief valve operable at a preset limit to prevent overpressurization. Petitioner contended that the AAPA in the ’533 specification itself established that nitrogen generators were well-known and commercially available. Finally, Petitioner asserted that Craig taught a two-valve “auxiliary condensate drain” that meets the limitations of the claimed “drum drip drain.”
    • Motivation to Combine: A POSITA would combine these references to create a reliable and cost-effective corrosion-resistant preaction system. The motivation to substitute a nitrogen generator for Golinveaux's pressurized gas source was to eliminate the need to monitor and replace gas tanks. The motivation to incorporate Craig's two-valve drain was to enable fluid removal from Golinveaux’s system without significant pressure loss, a standard practice required by industry codes like NFPA 13.
    • Expectation of Success: Petitioner argued that combining these known elements—a nitrogen-based preaction system, a standard nitrogen generator, and a conventional drum drip drain—would have been a straightforward substitution of known components for their predictable functions.

Ground 2: Claims 1-4, 7, 9, and 10 are anticipated by Burkhart under 35 U.S.C. §102.

  • Prior Art Relied Upon: Burkhart (Patent 8,720,591).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Burkhart, a single prior art reference, disclosed every element of the challenged claims. Specifically, Burkhart was argued to teach a preaction sprinkler system comprising a piping network, a nitrogen generator, a drum drip, and a vent operable at a preset or adjustable limit to purge oxygen. Petitioner also argued Burkhart explicitly disclosed the use of an oxygen sensor to control the nitrogen generator (for claims 3-4) and the capability of producing at least 90% nitrogen (for claim 7).

Ground 3: Claims 1-10 are obvious over Viking, NFPA 13, Cahill-O’Brien, and either EPRI or Wood.

  • Prior Art Relied Upon: Viking (“Dry Pipe Sprinkler System” brochure), NFPA 13 (“Standard for the Installation of Sprinkler Systems”), Cahill-O’Brien (Patent 5,438,841), and either EPRI (“Plant Layup and Equipment Preservation Sourcebook”) or Wood (Patent 6,540,028).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Viking taught a standard dry pipe sprinkler system that uses pressurized nitrogen and includes a drum drip. While Viking did not explicitly teach a preaction system, NFPA 13 established that such systems were well-known modifications of dry pipe systems. Cahill-O’Brien, in the analogous art of preventing oxidation in shipping containers, taught using a nitrogen generator and an oxygen sensor to create and control an inert atmosphere. The final element, a vent for purging oxygen, was taught by either EPRI or Wood. EPRI, from the analogous art of preventing power plant pipe corrosion, taught using an "air ejector vent" to maintain a purge flow of nitrogen. Alternatively, Wood disclosed a pressure-actuated vent on a condensate drain to automatically discharge fluid and gas.
    • Motivation to Combine: A POSITA would have been motivated to modify Viking's system to a preaction type per NFPA 13 to prevent accidental water discharge. To solve the known problem of corrosion, it would have been obvious to look to analogous arts like those in Cahill-O’Brien and EPRI, which used nitrogen generators and vents to displace oxygen. A POSITA would combine these teachings to create an automated, corrosion-resistant sprinkler system, using Wood's pressure-actuated vent as a known and predictable component to control the purge.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including a ground combining Golinveaux, AAPA, Craig, and Wagner (Patent 7,717,776) for claims 3-4, and another ground combining Burkhart with the parent patent application publication for claims 5-6 and 8.

4. Key Claim Construction Positions

  • "preaction": Petitioner argued that because the specification provides no definition, the term should be construed according to the National Fire Protection Association (NFPA) definition: "A sprinkler system employing automatic sprinklers that are attached to a piping system that contains air that might or might not be under pressure, with a supplemental detection system installed in the same areas as the sprinklers."
  • "drum drip": Petitioner contended this term is informal and undefined in the specification and industry standards. Based on extrinsic evidence, Petitioner proposed it should be construed to mean "a generally vertical section of pipe with an outlet and valve, attached to a dry pipe or preaction piping network at a low point, which allows residual water, condensate, and other fluids to drain... without loss of pressure in the piping network sufficient to trigger its actuation."

5. Key Technical Contentions (Beyond Claim Construction)

  • Effective Filing Date: Petitioner dedicated significant argument to establishing that claim 1 is not entitled to the priority date of its parent application. Petitioner argued that the parent application disclosed two distinct types of vents (a pressure relief valve and a purge vent) but did not disclose a single vent having the combined features recited in claim 1 (i.e., being both pressure-operated and for purging oxygen). Therefore, Petitioner contended this combination was new matter introduced in the application for the ’533 patent, making its effective priority date June 5, 2015, and rendering references like Burkhart available as prior art.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-10 of the ’533 patent as unpatentable.