Prosecution Insights
Last updated: April 19, 2026
Application No. 18/702,153

LEAKAGE DETECTION SYSTEM OF RELIQUEFACTION SYSTEM FOR SHIP

Non-Final OA §103
Filed
Apr 17, 2024
Examiner
ZEC, FILIP
Art Unit
3763
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Hanwha Ocean Co., Ltd.
OA Round
1 (Non-Final)
65%
Grant Probability
Favorable
1-2
OA Rounds
3y 1m
To Grant
79%
With Interview

Examiner Intelligence

Grants 65% — above average
65%
Career Allow Rate
649 granted / 998 resolved
-5.0% vs TC avg
Moderate +14% lift
Without
With
+14.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
31 currently pending
Career history
1029
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
52.1%
+12.1% vs TC avg
§102
23.2%
-16.8% vs TC avg
§112
15.6%
-24.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 998 resolved cases

Office Action

§103
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 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claim(s) 1 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication 2016/0216029 to Ragot (Ragot) in view of KR 2010-0086299 to Song (Song). In reference to claim 1, Ragot teaches leakage detection system of a reliquefaction system for ships (par 0004), comprising a gas supply line (8, FIG. 3) along which boil-off gas generated from a liquefied gas stored in a storage tank (2, FIG. 3) of a ship is supplied to a compressor (4, FIG. 3); a reliquefaction line (16, FIG. 3) along which the boil-off gas compressed by the compressor (4, FIG. 3) is cooled and reliquefied through a heat exchanger (60, FIG. 3) and is returned to the storage tank (2, FIG. 3); a refrigerant circulation line (24, FIG. 3) along which a refrigerant exchanging heat with the compressed boil-off gas in the heat exchanger (60, FIG. 3) is circulated; a refrigerant compressor (32, FIG. 3) disposed on the refrigerant circulation line (24, FIG. 3) to compress the refrigerant discharged from the heat exchanger (60, FIG. 3) after cooling the compressed boil-off gas; a refrigerant expander (30, FIG. 3) expanding and cooling the refrigerant compressed by the refrigerant compressor and having been cooled through the heat exchanger (60, FIG. 3) and supplying the cooled refrigerant back to the heat exchanger (60, FIG. 3), but does not teach a refrigerant charge line connecting an inventory tank filled with nitrogen to an upstream side of the refrigerant compressor on the refrigerant circulation line, wherein, upon initial start-up or restart of a reliquefaction process, the nitrogen is supplied to the upstream side of the refrigerant compressor via the refrigerant charge line to detect leaks in the refrigerant circulation line. Song teaches a reliquefaction apparatus of a liquefied natural gas carrier (FIG. 2) comprising a refrigerant charge line (220, FIG. 2) connecting an inventory tank (tank N2, FIG. 2) filled with nitrogen to an upstream side of the refrigerant compressor (230, FIG. 2) on the refrigerant circulation line, wherein, upon initial start-up or restart of a reliquefaction process, the nitrogen is supplied to the upstream side of the refrigerant compressor (230, FIG. 2) via the refrigerant charge line to detect leaks in the refrigerant circulation line (intended use recitation; said system in FIG. 2 is capable of performing said functional language) in order to control the supply amount of the refrigerant (fifth paragraph, midsection). Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Ragot, to include a refrigerant charge line connecting an inventory tank filled with nitrogen to an upstream side of the refrigerant compressor on the refrigerant circulation line, wherein, upon initial start-up or restart of a reliquefaction process, the nitrogen is supplied to the upstream side of the refrigerant compressor via the refrigerant charge line to detect leaks in the refrigerant circulation line, as taught by Song, in order to control the supply amount of the refrigerant. Allowable Subject Matter Claims 2-8 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. REASONS FOR ALLOWANCE The following is an examiner’s statement of reasons for allowance: The prior art does not anticipate nor render obvious the combination set forth in the independent claim, and specifically does not show a leakage detection system of reliquefaction system for ships having a first valve disposed on the refrigerant circulation line upstream of a junction between the refrigerant circulation line and the refrigerant charge line; a second valve disposed on the refrigerant circulation line between the refrigerant expander and the heat exchanger; and a third valve disposed on the refrigerant charge line. Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.” Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. See attached PTO-892 for relevant prior art. Any inquiry concerning this communication or earlier communications from the examiner should be directed to FILIP ZEC whose telephone number is (571)270-5846. The examiner can normally be reached Mon - Fri; 9-5. 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, JD Fletcher can be reached at 5712705054. 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. /FILIP ZEC/Primary Examiner, Art Unit 3763
Read full office action

Prosecution Timeline

Apr 17, 2024
Application Filed
Feb 21, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
65%
Grant Probability
79%
With Interview (+14.1%)
3y 1m
Median Time to Grant
Low
PTA Risk
Based on 998 resolved cases by this examiner. Grant probability derived from career allow rate.

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