Prosecution Insights
Last updated: August 14, 2026
Application No. 19/131,825

TRANSCRITICAL REFRIGERATION PRESSURE EXCHANGER

Non-Final OA §102§103§112
Filed
May 21, 2025
Priority
Nov 28, 2022 — provisional 63/428,260 +2 more
Examiner
GRAY, PAUL J
Art Unit
3753
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Energy Recovery Inc.
OA Round
1 (Non-Final)
78%
Grant Probability
Favorable
1-2
OA Rounds
1y 0m
Est. Remaining
88%
With Interview

Examiner Intelligence

Grants 78% — above average
78%
Career Allowance Rate
411 granted / 526 resolved
+8.1% vs TC avg
Moderate +10% lift
Without
With
+10.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 3m
Avg Prosecution
35 currently pending
Career history
560
Total Applications
across all art units

Statute-Specific Performance

§101
0.7%
-39.3% vs TC avg
§103
42.7%
+2.7% vs TC avg
§102
27.7%
-12.3% vs TC avg
§112
26.2%
-13.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 526 resolved cases

Office Action

§102 §103 §112
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Claim Objections Claim 2 is objected to because of the following informalities: In line 5 of claim 2, please amend “an closing edge” to instead recite --a closing edge--. Appropriate correction is required. Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 1-5, 7-14 and 20 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. The term “substantially” in claims 1-5, 7-14 and 20 is a relative term which renders the claim indefinite. The term “substantially” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Regarding claim 7, the recitation of “a second end cover” in line 1 is indefinite. This claim is dependent on claim 6 which already introduces a second end cover. It is not clear if Applicant is intending to define another end cover or not. Please amend the claim accordingly. Claim Rejections - 35 USC § 102 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claim(s) 1-4 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Anderson et al. (US 2016/0160881, hereafter “Anderson”). Regarding claim 1, Anderson discloses a pressure exchanger (PX) comprising: a rotor (166) configured to receive a first fluid, receive a second fluid (via 176 and 180), and exchange pressure between the first fluid and the second fluid, wherein the rotor forms a plurality of ducts (190); and a first end cover (186) fluidly coupled with the rotor, the first end cover forming a first kidney (200), wherein a kidney angular extent of the first kidney is substantially an integer multiple of a duct angular spacing between at least two adjacent ducts of the plurality of ducts, wherein the kidney angular extent is an angular distance between an opening edge and a closing edge of the first kidney and the duct angular spacing is an angular distance between corresponding centers of the at least two adjacent ducts (para. [0058] – [0063]; Figs. 2-9). Regarding claim 2, Anderson further discloses the PX of claim 1, further comprising a second end cover (184) fluidly coupled with the rotor, wherein the second end cover forms a second kidney (196), wherein a delay angle between the first kidney of the first end cover and the second kidney of the second end cover ranges from 15 to 20 degrees, and wherein the delay angle is an angular distance between a closing edge of the second kidney and an closing edge of the first kidney. (the system of Anderson is capable of meeting this angle when the first or second end cover are rotated during operation as disclosed in para. [0058] – [0063]; Figs. 2-9) Regarding claim 3, Anderson further discloses the PX of claim 1, wherein the rotor forms the ducts in a plurality of concentric rows, wherein the rows are staggered. (Fig. 9) Regarding claim 4, Anderson further discloses the PX of claim 1, further comprising a second end cover (184), wherein the second end cover forms a second kidney (196), the first end cover comprising a first end cover surface (the surface of 186 that faces 166) that faces the rotor, the first end cover surface forming a buffer chamber (202) disposed in a delay region of the first end cover (Figs. 2-3), wherein the delay region is a region between an opening edge of the second kidney and an opening edge of the first kidney. (the opening edges are interpreted as the edges along the outer surface of 186 and 184; Figs. 2-3) Claim(s) 6-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Morphew (US 2016/0160888). Regarding claim 6, Morphew discloses a pressure exchanger (PX) comprising: a rotor (166) configured to receive a first fluid, receive a second fluid (via 176 and 180), and exchange pressure between the first fluid and the second fluid, wherein the rotor forms a plurality of ducts (192); a first end cover (186) fluidly coupled with the rotor, the first end cover comprising a first end cover surface (the surface of 186 that faces 166) that faces the rotor, the first end cover surface forming a buffer chamber (222) disposed in a delay region of the first end cover 9para. [0037]), wherein the first end cover forms a first kidney (200); and a second end cover (184) forming a second kidney (196), wherein the delay region is a region between an opening edge of the second kidney and an opening edge of the first kidney (Figs. 2-11). Regarding claim 7, Morphew further discloses the PX of claim 6, further comprising a second end cover fluidly coupled to the rotor, the second end cover forming a third kidney (202), wherein when a first duct of the plurality of ducts substantially aligns with the buffer chamber, the third kidney substantially aligns with the first duct. (Figs. 2-11) Regarding claim 8, Morphew further discloses the PX of claim 7, wherein the first duct and a second duct of the plurality of ducts substantially align with the buffer chamber simultaneously while the third kidney substantially aligns with the first duct. (Figs. 2-11) Regarding claim 9, Morphew further discloses the PX of claim 8, wherein the third kidney is a high pressure out (HPOUT) kidney and the first and second ducts are low-pressure ducts. (the third kidney is capable of operating in this manner such that all structural and functional limitations are met) Regarding claim 10, Morphew further discloses the PX of claim 9, wherein the first kidney is a high pressure in (UPIN) kidney, and the first duct substantially aligns with the first kidney after aligning with the buffer chamber. (the first kidney is capable of operating in this manner such that all structural and functional limitations are met; Figs. 2-11) Regarding claim 11, Morphew further discloses the PX of claim 8, wherein the third kidney is a low pressure out (LPOUT) kidney and the first and second ducts are high pressure ducts. (the third kidney and ducts are capable of operating in this manner such that all structural and functional limitations are met) Regarding claim 12, Morphew further discloses the PX of claim 11, wherein the first kidney is a low pressure in (LPJIN) kidney, and the first duct substantially aligns with the first kidney after aligning with the buffer chamber. (the first kidney is capable of operating in this manner such that all structural and functional limitations are met; Figs. 2-11) Regarding claim 13, Morphew further discloses the PX of claim 7, wherein a kidney angular extent of the first kidney is substantially an integer multiple of a duct angular spacing between at least two adjacent ducts of the plurality of ducts, wherein the kidney angular extent is an angular distance between an opening edge and a closing edge of the first kidney and the duct angular spacing is an angular distance between corresponding centers of the at least two adjacent ducts. (para. [0033] – [0041]; Figs. 2-11) Regarding claim 14, Morphew further discloses the PX of claim 7, wherein the buffer chamber is a substantially similar shape as the first kidney and has an angular extent substantially equal to or substantially double an angular extent of a rotor duct of the plurality of ducts. ( Figs. 2-11) Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Anderson. Regarding claim 5, Anderson further discloses the PX of claim 1, wherein the first end cover forms a third kidney (202), wherein fluid flow between ports of the PX and the rotor is through the first kidney and the third kidney, but fails to disclose wherein a ratio of a size of the first kidney to a size of the third kidney ranges from 3:2 to 5:2. It would have been obvious to a person having ordinary skill in the art before the effective filing date of the application to modify a ratio of a size of the first kidney to a size of the third kidney ranges from 3:2 to 5:2 since such a modification would involve a mere change in the size of a component (A change in size is generally recognized as being within the level of ordinary skill in the art). The motivation for doing so would be to provide an optimized size and shape of the opening as desired based on user defined criteria. Claim(s) 15-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Morphew. Regarding claim 15, Morphew further discloses the PX of claim 6, wherein the first end cover forms a third kidney (202), wherein fluid flow between ports of the PX and the rotor is through the first kidney and the third kidney, but fails to disclose wherein a ratio of a size of the first kidney to a size of the second kidney ranges from 3:2 to 5:2. It would have been obvious to a person having ordinary skill in the art before the effective filing date of the application to modify a ratio of a size of the first kidney to a size of the second kidney ranges from 3:2 to 5:2 since such a modification would involve a mere change in the size of a component (A change in size is generally recognized as being within the level of ordinary skill in the art). The motivation for doing so would be to provide an optimized size and shape of the opening as desired based on user defined criteria. Regarding claim 16, Morphew discloses a pressure exchanger (PX) comprising: a rotor (166) configured to receive a first fluid, receive a second fluid (via 176 and 180), and exchange pressure between the first fluid and the second fluid; and a first end cover (186) fluidly coupled with the rotor, the first end cover forming a first kidney (200) and a second kidney (202), wherein fluid flow between ports of the PX and the rotor is through the first kidney and the second kidney ( Figs. 2-11), but fails to disclose wherein a ratio of a size of the first kidney to a size of the second kidney ranges from 3:2 to 5:2. It would have been obvious to a person having ordinary skill in the art before the effective filing date of the application to modify a ratio of a size of the first kidney to a size of the second kidney ranges from 3:2 to 5:2 since such a modification would involve a mere change in the size of a component (A change in size is generally recognized as being within the level of ordinary skill in the art). The motivation for doing so would be to provide an optimized size and shape of the opening as desired based on user defined criteria. Regarding claim 17, Morphew further discloses the PX of claim 16, wherein the first kidney is a high-pressure kidney, and the second kidney is a low-pressure kidney. (each kidney is capable of operating in this manner such that all structural and functional limitations are met; Figs. 2-11) Regarding claim 18, Morphew further discloses the PX of claim 17, further comprising a second end cover (184) fluidly coupled with the rotor, the second end cover forming a third kidney (196) and a fourth kidney (198), wherein fluid flow between ports of the PX and the rotor is through the third kidney and the fourth kidney, but fails to disclose wherein a ratio of a size of the third kidney to a size of the fourth kidney ranges from 3:2 to 5:2. It would have been obvious to a person having ordinary skill in the art before the effective filing date of the application to modify a ratio of a size of the third kidney to a size of the fourth kidney ranges from 3:2 to 5:2 since such a modification would involve a mere change in the size of a component (A change in size is generally recognized as being within the level of ordinary skill in the art). The motivation for doing so would be to provide an optimized size and shape of the opening as desired based on user defined criteria. Regarding claim 19, Morphew further discloses the PX of claim 18, wherein the third kidney is a high-pressure kidney, and the fourth kidney is a low-pressure kidney. (each kidney is capable of operating in this manner such that all structural and functional limitations are met; Figs. 2-11) Regarding claim 20, Morphew further discloses the PX of claim 16, wherein the rotor forms a plurality of ducts (192), wherein a kidney angular extent of the first kidney is substantially an integer multiple of a duct angular spacing between at least two adjacent ducts of the plurality of ducts, wherein the kidney angular extent is an angular distance between an opening edge and a closing edge of the first kidney and the duct angular spacing is an angular distance between corresponding centers of the at least two adjacent ducts. (para. [0033] – [0041]; Figs. 2-11) Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to PAUL J GRAY whose telephone number is (571)270-0544. The examiner can normally be reached 9:00 am - 5:00 pm, Monday - Friday. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Kenneth Rinehart can be reached at 571 272-4881. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /PAUL J GRAY/Primary Examiner, Art Unit 3753
Read full office action

Prosecution Timeline

May 21, 2025
Application Filed
Jul 16, 2026
Non-Final Rejection mailed — §102, §103, §112 (current)

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Prosecution Projections

1-2
Expected OA Rounds
78%
Grant Probability
88%
With Interview (+10.1%)
2y 3m (~1y 0m remaining)
Median Time to Grant
Low
PTA Risk
Based on 526 resolved cases by this examiner. Grant probability derived from career allowance rate.

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