Grant of a patent to a defendant does not provide a defense against infringement of a prior patent
Introduction: The case of Aquestia Limited v. Automat Industries Private Limited represents a significant judicial examination of patent infringement within the realm of fluid control valve technology. This legal dispute centers on allegations that the defendants' product, marketed under the "Hydromat" brand, infringes the plaintiff’s registered patent, IN 427050, titled "A Fluid Control Valve." The case raises critical questions about patent claim construction, the relevance of a defendant’s own patent as a defense to infringement, and the role of prior employment relationships in intellectual property disputes.
Factual Background: Aquestia Limited, the plaintiff, is a company with a robust portfolio of approximately 145 patents, specializing in the development of advanced valve technologies, including mechanical and hydraulic valves. The suit patent, IN 427050, pertains to a fluid control valve characterized by an asymmetric sealing diaphragm, which enhances low-pressure operation and fluid flow control. This patent, originally granted to Dorot Management Control Valves Ltd., was assigned to Aquestia following a merger. The plaintiff has achieved significant commercial success, with global revenues exceeding USD 100 million in 2023 and sales of approximately 28,000 units of the patented valves, generating around USD 5 million. The plaintiff’s products are distributed in multiple countries, including India, through established trade channels.
The defendants, led by Automat Industries Private Limited, are engaged in the manufacture and sale of irrigation solutions, including valves branded as "Hydromat." Defendant no. 5, a former employee of Netafim (the plaintiff’s distributor), joined Automat Industries as Chief Technology Officer in March 2020. The plaintiff alleges that defendant no. 5, during his tenure at Netafim from 2013 to 2019, was privy to technical details of the suit patent, particularly the "Series 75 Valve" technology. In January 2023, the plaintiff became suspicious of the defendants’ activities upon learning of defendant no. 5’s role and the announcement of the Hydromat valves, which were promoted for their "Cured Bridge" innovation. Subsequent investigations, including purchases of Hydromat valves in October 2023 and February 2024, confirmed the plaintiff’s belief that these valves infringed the suit patent. The plaintiff conducted detailed examinations, comparing the defendants’ product to the suit patent’s claims, and initiated legal action in October 2024.
The defendants, in response, assert that their Hydromat valves are covered by their own patent, IN 536, which features a curved sealing bridge designed to reduce turbulence and energy loss. They argue that their product is distinct from the plaintiff’s invention and deny any infringement. Additionally, they claim that defendant no. 5 was only involved in commercial aspects during his time at Netafim and lacked access to the suit patent’s technical details. The defendants further allege that the plaintiff’s suit is motivated by mala fide intent to stifle competition and is barred by delay and laches.
Procedural Background: The plaintiff filed the suit, CS (COMM) 860/2024, seeking a permanent injunction to restrain the defendants from infringing the suit patent, IN 427050, along with other ancillary reliefs. Concurrently, the plaintiff filed an application, I.A. 4111/2024, under Order XXXIX Rules 1 and 2 of the Code of Civil Procedure, 1908, for an interim injunction to prevent the defendants from manufacturing, selling, or exporting the Hydromat valves. The plaintiff also initiated a revocation petition, CO (COMM.IPD-PAT) 1/2025, challenging the validity of the defendants’ patent, IN 536. The defendants filed written statements denying infringement and asserting the protection of their own patent.
Core Dispute:The central issue in this case is whether the defendants’ Hydromat valves infringe the plaintiff’s patent, IN 427050, specifically its independent Claim 1, which describes a fluid control valve with an asymmetric sealing diaphragm and differential diaphragm surface areas. The plaintiff contends that the defendants’ product incorporates these novel features, as evidenced by measurements showing unequal diaphragm areas (4900 mm² on the inlet side versus 4488 mm² on the outlet side). The defendants argue that their product, covered by patent IN 536, features a distinct curved sealing bridge and operates on different technical principles, thus not infringing the suit patent. They further assert that their patent was granted after the Indian Patent Office considered the suit patent as prior art, establishing its non-infringing nature. Additionally, the defendants raise defenses of delay, laches, and lack of commercial presence by the plaintiff in India. The involvement of defendant no. 5, a former employee with potential access to the plaintiff’s technical know-how, adds a layer of complexity, raising questions about the misuse of confidential information.
Discussion on Judgments: Several judgments were cited by the parties to support their respective positions, each providing context to the legal arguments advanced. The plaintiff relied on Hindustan Lever Limited v. Lalit Wadhwa (2007 SCC OnLine Del 1077), arguing that the mere grant of a patent to the defendants does not provide immunity against infringement of the plaintiff’s prior patent. This judgment clarifies that a patent confers an exclusionary right under Section 48 of the Patents Act, 1970, to prevent others from using the patented invention but does not grant the patentee the right to infringe another’s patent. The plaintiff emphasized that the defendants’ patent, IN 536, does not negate the possibility of infringing the suit patent, as the court must compare the defendants’ product with the claims of the suit patent.
The plaintiff also cited Biswanath Prasad Radhey Shyam v. Hindustan Metal Industries ((1979) 2 SCC 511), where the Supreme Court underscored the importance of the complete specification in infringement proceedings. This judgment supports the plaintiff’s approach of focusing on the claims of the suit patent, particularly the novel features of the asymmetric sealing diaphragm and differential diaphragm areas, to establish infringement.
The defendants referenced Boehringer (2021 SCC OnLine Del 5383), arguing that public interest considerations, such as access to affordable products, should influence the grant of an injunction. However, the court distinguished this case, noting that Boehringer involved public health and access to affordable medicine, which is not applicable to the present case involving irrigation valves.
Both parties cited a 2024 judgment (2024 SCC OnLine Del 5510), though its repeated mention in the document suggests it was referenced multiple times by the defendants to support their non-infringement claims, possibly emphasizing technical distinctions or procedural aspects. Additionally, the plaintiff relied on a 2025 judgment (2025 SCC OnLine Del 4681) and another 2025 case (2025 SCC OnLine Del 4883), likely to reinforce the principles of claim construction and infringement analysis. The court also considered Guala Closures (specific citation not provided in the document but referenced), where a coordinate bench analyzed infringement by comparing the suit patent with the defendant’s product, irrespective of the defendant’s own patent.
Reasoning and Analysis of the Judge: The judge adopted a claim-to-product comparison, as mandated by legal precedent, rather than the defendants’ product-to-product approach. The novel features of Claim 1 of the suit patent, namely the asymmetric sealing diaphragm and differential diaphragm surface areas, were found to be present in the defendants’ Hydromat valves. The plaintiff’s claim mapping, supported by measurements (4900 mm² versus 4488 mm²), established that the defendants’ diaphragm was asymmetric, with a larger area over the inlet path, aligning with the suit patent’s claims. The defendants’ failure to provide specific measurements or rebuttal evidence weakened their non-infringement argument.
The judge addressed the defendants’ reliance on their patent, IN 536, by citing Hindustan Lever, which clarifies that a patent does not confer a positive right to practice the invention if it infringes an earlier patent. The defendants’ patent specification itself admitted to unequal areas on the upstream and downstream sides, contradicting their claim of a symmetric diaphragm. Furthermore, the suit patent’s Claim 1 does not specify the shape of the sealing bridge, and dependent Claim 9 explicitly includes a curved sealing bridge, negating the defendants’ argument that their curved bridge design distinguishes their product.
Regarding defendant no. 5, the judge examined confidential email communications from 2015–2016, which demonstrated that defendant no. 5 was involved in technical discussions about the plaintiff’s valve technology during his tenure at Netafim. His technical qualifications and role as an inventor in the defendants’ patent further undermined his claim of being solely involved in commercial aspects. This raised a prima facie case of potential misuse of technical know-how.
On the issue of delay, the judge found the plaintiff’s explanation—spanning investigations from November 2022 to product testing in August 2024—cogent and sufficient, dismissing the defendants’ claim of laches. The plaintiff’s evidence of sales in India since May 2021 also rebutted the defendants’ argument about lack of commercial presence. The judge concluded that the plaintiff established a prima facie case of infringement, with irreparable harm and a balance of convenience favoring the grant of an interim injunction.
Final Decision: The court granted the plaintiff’s application for an interim injunction, restraining the defendants, their partners, employees, agents, and related parties from making, using, selling, distributing, advertising, exporting, or importing any product that infringes the suit patent, IN 427050. The defendants were further directed to remove all listings and references to the infringing Hydromat valves from e-commerce and their own platforms. The court clarified that these observations were for the purpose of the interim application and would not influence the final outcome of the suit.
Law Settled in This Case: This case reinforces several key principles of patent law in India. First, it reaffirms that the grant of a patent to a defendant does not provide a defense against infringement of a prior patent, as a patent confers only an exclusionary right under Section 48 of the Patents Act, 1970. Second, it emphasizes the importance of claim-to-product analysis in infringement proceedings, focusing on the novel features outlined in the patent’s claims, as supported by Biswanath Prasad Radhey Shyam. Third, the case clarifies that the shape of a component (e.g., a curved versus straight sealing bridge) is immaterial if the patent’s claims cover both embodiments. Finally, it underscores the relevance of prior employment relationships in assessing potential misuse of technical know-how, particularly when supported by documentary evidence. These principles guide courts in evaluating patent infringement claims and balancing the rights of patentees with competitive market dynamics.
Case Title: Aquestia Limited Vs. Automat Industries Private Limited
Date of Order: 01.08.2025
Case Number: CS (COMM) 860/2024
Neutral Citation: 2025:DHC:6312
Name of Court: High Court of Delhi
Name of Judge: Hon’ble Mr. Justice Amit Bansal
Disclaimer: The information shared here is intended to serve the public interest by offering insights and perspectives. However, readers are advised to exercise their own discretion when interpreting and applying this information. The content herein is subjective and may contain errors in perception, interpretation, and presentation.
Written By: Advocate Ajay Amitabh Suman, IP Adjutor [Patent and Trademark Attorney], High Court of Delhi
