GD Energy Products LLC v. Kerr Machine Co

1. Case Identification

• Case #: PGR2025-00031
• Patent #: 12,152,582
• Filed: February 6, 2025
• Petitioner(s): GD Energy Products, LLC
• Patent Owner(s): Kerr Machine Company
• Challenged Claims: 1-15

2. Patent Overview

• Title: Fluid End Assembly
• Brief Description: The ’582 patent discloses a fluid end assembly for a multiplex reciprocating pump. The purported novelty is a design that seals fluid flow bores using a single, large plate fastened to the exterior of the housing to cover multiple adjacent bore openings, thereby eliminating the need for individual threaded retaining nuts for each bore.

3. Grounds for Unpatentability

Ground 1: Claims 1-14 are obvious over Kerr.

• Prior Art Relied Upon: Kerr (Kerr KP-3300HP Plunger Pump Service Manual), a printed publication publicly available before the patent’s priority date.
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that the Kerr manual, which describes a conventional triplex plunger pump, explicitly discloses every element of claims 1-14. Specifically, Kerr illustrates a fluid end assembly with a monoblock housing, multiple horizontal and vertical bores forming internal chambers, and plungers. Crucially, Petitioner contended that Kerr’s design includes a single cover plate fastened to the housing that covers all three horizontal bores, directly teaching the key limitation of the ’582 patent. For claim elements reciting a "second" plunger arrangement (e.g., a second bore, second pair of valves), Petitioner asserted these would be obvious because Kerr describes a triplex pump, and a person of ordinary skill in the art (POSITA) would understand that each of the three plunger assemblies is structurally identical.
  • Motivation to Combine (for §103 grounds): This ground is asserted as a single-reference obviousness challenge, arguing Kerr itself renders the claims obvious without combination.
  • Expectation of Success (for §103 grounds): Not applicable as a single-reference ground.

Ground 2: Claims 1-14 are obvious over Aplex in view of Stanton.

• Prior Art Relied Upon: Aplex (Dupagro Aplex SC65 Manual) and Stanton (Application # 2005/0200081).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Aplex, like Kerr, discloses a conventional triplex pump fluid end with a housing, multiple bores, and a single plate covering the horizontal bores. However, Aplex’s stuffing box is bolted to the exterior of the fluid end. Stanton was introduced because it discloses a different, well-known stuffing box arrangement where the packing sleeve is at least partially installed within the fluid end’s horizontal bore. The proposed combination replaces Aplex's external stuffing box with Stanton's internal packing assembly to arrive at the claimed invention.
  • Motivation to Combine (for §103 grounds): A POSITA would combine these references to improve the pump’s performance. Petitioner argued that installing the packing assembly partially within the fluid end housing, as taught by Stanton, provides better pressure and fluid isolation compared to the external arrangement shown in Aplex. This would have been a simple and predictable substitution of one known packing method for another.
  • Expectation of Success (for §103 grounds): A POSITA would have a high expectation of success, as combining these known components involves applying predictable mechanical principles.

Ground 3: Claims 1-14 are obvious over Blume in view of Stanton and Wilkinson.

• Prior Art Relied Upon: Blume (Patent 7,186,097), Stanton (Application # 2005/0200081), and Wilkinson (Patent 4,773,833).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner asserted that Blume discloses a conventional triplex pump fluid end but uses individual threaded retainers to cover its bores, not a single plate. Wilkinson was introduced to supply the missing plate limitation, as it explicitly teaches using a bolted-on plate ("plate 44") to cover and access multiple bores in a fluid end. Stanton was again used to teach the claimed internal packing sleeve and nut arrangement, which would replace the different packing assembly shown in Blume.
  • Motivation to Combine (for §103 grounds): A POSITA would combine Blume and Wilkinson because using a cover plate (from Wilkinson) instead of individual threaded retainers (from Blume) is a well-known design alternative for securing plugs in a fluid end. The choice is a simple substitution of one known retention method for another with predictable results. A POSITA would further be motivated to incorporate Stanton's packing assembly for its benefits, such as easier repair of damaged threads (by replacing a sleeve instead of the entire housing) and simpler adjustment of packing pressure.
  • Expectation of Success (for §103 grounds): A POSITA would expect success in implementing these known design alternatives to achieve a predictable and functional fluid end assembly.

• Additional Grounds: Petitioner asserted that claims 1-14 are also invalid over an offer for sale of the Kerr Pump, which occurred more than one year prior to the patent’s priority date. Petitioner further asserted that claim 15 is indefinite under 35 U.S.C. §112 for lacking antecedent basis for "the plurality of fasteners" and for being unclear how fasteners used to attach the plate to the housing could also attach a retainer to an internal component.

4. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under §324 (Fintiv) by stating that there are no co-pending proceedings related to the ’582 patent, making the Fintiv factors inapplicable or weigh against denial.
• Petitioner also argued against denial under §325(d), contending that the art and arguments presented are not substantially the same as those considered during prosecution. The primary references of Kerr and Aplex were never before the examiner. While Wilkinson was cited during prosecution, it was combined with a different reference (Orr), and the Patent Owner distinguished it on grounds not relevant to the current petition. Furthermore, Petitioner argued the examiner materially erred by allowing the claims based on a mistaken belief that the claimed "plate" required openings, a limitation that had been cancelled from the claims.

5. Relief Requested

• Petitioner requests institution of post-grant review and cancellation of claims 1-15 of the ’582 patent as unpatentable.