Patented But Still Infringing: Delhi HC Stops Hydromat Valve Sales

Close-up view of industrial metal control valves and piping system, showing aged and weathered valve wheels used for regulating fluid flow. Featured image for article: Patented But Still Infringing: Delhi HC Stops Hydromat Valve Sales

Summary

In the case of Aquestia Limited vs Automat Industries Private Limited & Ors., the Delhi High Court granted an interim injunction restraining the defendants from manufacturing and selling their ‘Hydromat’ valves. The court held that even a patented product can infringe an earlier patent, and found that the defendants’ valves incorporated the core features of the plaintiff’s fluid control valve patent claims.

Patent Infringement Claims

Aquestia Limited, an Israeli company engaged in control and management of liquid conveyance systems, owns Indian Patent No. 427050 for a fluid control valve. The invention features an asymmetric sealing diaphragm, with the portion over the inlet side having a larger area than the portion over the outlet side, resulting in improved performance at low pressure and reduced diaphragm drift.

The defendants launched ‘Hydromat’ valves, claiming protection under their own Indian Patent No. 478536. One of the inventors of this later patent had earlier worked with Netafim, the plaintiff’s distributor, and had been involved in the development of the plaintiff’s valve technology.

The plaintiff alleged that the Hydromat valves were covered under its patent claims and relied on Claim 1, which described a fluid control valve where:

“… the sealing diaphragm is asymmetric with respect to an apex thereof, and a portion of the sealing diaphragm extending from the apex over the inlet path has larger area than a portion … over the outlet path.”

Tests conducted by the plaintiff showed the defendants’ diaphragm area on the inlet side measured about 4,900 mm² compared to about 4,485 mm² on the outlet side – matching the claimed configuration. It argued that the “curved sealing bridge” promoted by the defendants was irrelevant to infringement because Claim 1 covered sealing bridges of any shape, with dependent claims expressly including curved or concave forms.

Defendants’ Contentions

The defendants contended that their own granted patent shielded them from infringement claims, that their diaphragm was symmetrical, and that the curved sealing bridge was a novel feature absent from the plaintiff’s patent. They also raised objections of delay, absence of Indian sales, and public interest concerns linked to supply for government projects.

Court on Patent Immunity

The court clarified that owning a granted patent does not give the patentee a right to practise their invention if it infringes an earlier valid patent. Under Indian law, a patent grants only an exclusionary right – the right to stop others from using the patented invention – and does not automatically allow the patent holder to use their own product if it falls within the scope of another’s prior patent.

Referring to precedent, the court emphasised that a later patent holder could still be an infringer, and infringement must always be determined through claim-to-product comparison, not by comparing one product to another.

Claim Comparison and Infringement Analysis

The court undertook a claim mapping exercise comparing Claim 1 of the suit patent with the defendants’ Hydromat valve.

Feature from Claim 1 of Suit PatentFinding in Hydromat ValveCourt’s Conclusion
Sealing diaphragm is asymmetric with respect to the apexDiaphragm divided by a concave rib through the apex, areas visibly unequalMatches claim
Portion of diaphragm over inlet path larger than portion over outlet pathMeasured inlet area: ~4,900 mm²; outlet area: ~4,485 mm²Matches claim
Sealing bridge - shape not limited (straight or curved)Defendants’ bridge curved; dependent claim of suit patent includes curved shapeCovered within claim scope

The court noted that the defendants had not rebutted the plaintiff’s measurements with any evidence. Further, the  Court stated that the defendants’ own patent specification admitted that the upstream (inlet) area was larger – consistent with the suit patent’s configuration. Based on this mapping, the court found that the Hydromat valves fell squarely within the scope of Claim 1 of the plaintiff’s patent.

The court also took note of evidence showing that the former employee involved in the defendants’ patent had participated in technical discussions on the plaintiff’s valve during his earlier role.

Rejection of Delay and Sales Defences

The court accepted the plaintiff’s explanation for the delay in filing the suit, which included operational disruptions due to the October 2023 terrorist attack near its Israeli facilities. Invoices showed sales in India since 2021, disproving the claim of no commercial presence.

Interim Injunction Order

The court held that the plaintiff had established a prima facie case of infringement, with the balance of convenience in its favour and risk of irreparable harm. It restrained the defendants from manufacturing, selling, exporting, or otherwise dealing in the infringing products, and directed the removal of listings from all platforms.

Case Citation: Aquestia Ltd. v. Automat Indus. Pvt. Ltd. & Ors., CS (COMM) 860/2024, 2025 SCC OnLine Del 4883 (India), available at https://indiankanoon.org/doc/113756547/ (last visited Aug. 12, 2025).

Author: Dr. Kalyan Kankanala

Dr. Kalyan Kankanala is a practicing intellectual property (IP) attorney and author. He is a senior partner at BananaIP Counsels, a well-known IP firm based in Bangalore, India. His writings cover a range of topics relating to IP law, business, and policy, and he has authored several books and articles in the field. He has been contributing to this blog since 2007. The views expressed here are his own and do not represent those of BananaIP Counsels or its members.

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