Patent Claims in Water-Treatment Systems: Capturing Commercial Value

Introduction : Consider a small Indian company that builds a water purifier which cleans borewell water using half the usual electricity. It has a special filter, a self-cleaning cycle and a small computer that adjusts the machine to the incoming water. The company files a patent. Two years later, a competitor sells a near-identical machine with a different filter material and a slightly changed cleaning routine. Since the company's patent talks about its own creation only, then the competitor's product doesn't come under it.

The stakes are rising. A Share India Securities report projects that India's water and wastewater market will grow at about 11.6 per cent a year to USD 17.9 billion by FY29, while only around 30 per cent of the country's wastewater is currently treated.1 In such a market, one product usually contains three inventions: the hardware (filters, membranes, tanks, electrodes), the process (the steps that clean the water) and the software (the controls that run it). Each can be copied, licensed or sold separately.

This blog explains what the Patents Act, 19702 requires of a patent application, how the description of an invention limits the claims that can be made, how wide those claims should be, and how businesses can record useful variations before filing. It ends with a short system-roadmap checklist.

Legal Provisions

A. The Patents Act, 1970

A patent can be pictured as a plot of land. The claims are the fence that marks the boundary, and the specification (the detailed written description) is the map. The provisions below together ensure that the fence is never larger than the map.

Sections 10(4) and 10(5) require the complete specification to fully describe the invention and how to perform it, to disclose the best method known to the applicant, and to end with claims that are clear, concise and "fairly based" on the matter disclosed.3 Put into simple language, a trained engineer must be able to construct the invention from the description, the inventor cannot withhold its best form, and it must not claim more than it has described.

Section 59(1) governs changes after filing. An applicant may make amendments only through disclaimer, correction, or explanation. Amended specification cannot include something that was not essentially already there, and amended claim must necessarily be confined to what was originally claimed.4 In reality, the door closes once the filing date is set. For instance, let’s assume that the inventors realize much later that the electrode cell functions equally well with titanium and stainless steel. It would be too late to mention the use of titanium. The only route is a fresh application with a later date, and by then a competitor may have got there first.

Section 64(1)(h) and (i) deal with what happens after grant. Anyone interested or the Central Government may approach the High Court for cancellation of the patent, and any person charged with patent infringement may bring in similar arguments as counterclaims. There are two primary grounds matter here. Under clause (h), a patent can be revoked if its description is not enough for a person of average skill in India to work the invention, or if the best method was held back. Clause (i) allows for its revocation when a claim is either ambiguous or not reasonably grounded on the disclosed information.5 Thus a weak specification is a major issue not only during examinations. It also gives any competitor who is later sued a ready line of attack.

Sections 48 and 104A set out the patentee’s rights. A product patent lets the owner stop others from making, using, offering for sale, selling or importing the product in India; a process patent covers use of the process and the product obtained directly by it. Where a patent covers a process for obtaining a new product, a court may ask the defendant to prove that its own process is different.6

Section 3 lists what is not an invention. Four clauses matter most here: clause (d), a new use of a known substance or the mere use of a known process or machine; clause (e), a mere mixture whose components only add up their known properties; clause (f), a mere arrangement of known devices working independently in a known way; and clause (k), mathematical or business methods, computer programmes per se and algorithms.

B. Filing Rules and Patent Office Guidelines

Under Section 9, an applicant may first file a provisional specification to secure a filing date and then file the complete specification within twelve months. While Section 16 enables filing of a divisional application for another invention described in the original patent application prior to grant, Section 31 provides only a limited grace period for prior disclosures.8

The Patents (Amendment) Rules, 2024 added Rule 13(2A), which confirms that a divisional may rest on any distinct invention disclosed in the specification and not only on what was first claimed.9 The same Rules reduced the time for requesting examination to 31 months for applications filed on or after 15 March 2024.

On 29 July 2025, the Patent Office issued the Guidelines for Examination of Computer Related Inventions (CRIs), 2025, after two rounds of public consultation.11 Their key question revolves around the presence of a technical effect or contribution of a technical nature, and they have a full chapter devoted to artificial intelligence and sufficiency of disclosure.

Legal Analysis

A. One Product, Three Inventions

Filter cartridges and membrane modules fall under hardware and are thus protectable using product claims. These are the easiest to enforce, because a competitor's product can be bought and examined. Process claims, covering treatment steps, dosing or cleaning cycles, are valuable but harder to police, since the process usually runs inside a customer's plant. Section 104A offers only partial relief, because it applies mainly where the process yields a new product.

Control software raises the Section 3(k) question. One view is that software which controls a physical process with a measurable result makes a technical contribution. Commentators reviewing the 2025 draft guidelines note that their list of recognised technical effects includes real-time monitoring and control of devices that solves a technical problem.13 One example would be a dosing system which uses sensors to reduce energy or chemical usage. A stricter view holds that adding a pump or sensor to an algorithm should not convert an excluded method into an invention. The disclosure burden is also rising: the Madras High Court has stressed that AI-related inventions must be described in enough detail for their functioning to be reproduced.14 Applicants should therefore describe control logic as concrete steps acting on named equipment, with the technical result stated and supported by data.

B. Support in the Specification

When the specification indicates that there is polyamide membrane that has been tested in one flow rate, then the mentioning of “any membrane” will no longer be justified by the specification under Section 10(5). Practitioners note that Indian Controllers have rejected applications purely on grounds of insufficient disclosure, without raising issues about novelty or inventive step, and each claim needs at least one described embodiment.15 Where the specification describes polymer, ceramic, and metal membranes, and explains how each affects the conditions of operation and provides data on all types of feed water, a wider claim can be justified.

However, there is a price to pay for that. The full disclosure of the know-how of the process by the specification means that competitors can see it, and the best-method condition of Section 10(4)(b) means the preferred setting cannot be kept as a trade secret.

C. Claim Breadth

An overly broad claim runs the risk of being considered unpatentable because of lack of novelty or inventive step; an overly narrow claim invites design-around. The following test may be useful: for every aspect of the invention which appears in the prototype, is there a way that the competitor could substitute something else that will accomplish the same result? If so, the feature goes into a dependent claim, with the alternatives set out in the specification.

It is helpful to cover the invention from a number of angles, namely, the system as a whole, the method for treating water, the method for upgrading an existing installation, the controller, and the replaceable cartridge that ensures repeat business. Ranges of pH, flow, and dose must be provided as broad, preferred, and specific values in case a broad claim gets into trouble.

Both broad claims and broad disclosures have their detractors. Commentators on public interest concerns point to the potential impact of broad patents on essential services like clean water; to some extent, the issue is addressed by the compulsory licensing provisions of Chapter XVI.16 A former member of the Intellectual Property Appellate Board has also warned that liberal divisional practice may tempt applicants to over-disclose, producing long and complex specifications that do not always serve the public.1

D. Recording Variations Before Filing

Variations are most easily captured before the filing, when the inventors remember what they have tried. After the filing of the application, no new matter can be added under Section 59.4 A brief meeting with the engineers, product managers, sales people, and patent attorney will help reveal the variations. Engineers know what alternative methods exist, sales people know what the customer wants, and product managers know what the next product should have.

Consider the example of a membrane filter company. It may have tested polymer, ceramic, and metal membranes at various pressures and found that the cheap polymer clogged by the twentieth cycle. Each of these variations should be captured in the invention disclosure form along with the test results and date. Even the failed variation of the polymer membrane is useful as it can help show the inventive step in choosing the selected material.

That documentation must then feed into the provisional specification. According to Section 11(2), a claim will maintain the earlier date of the provisional only if it is fairly based on the matter disclosed in the provisional.18 Any variation left out of the provisional will get a later date, giving a competitor time to file first. Applicants must also file prior to pilot testing, tenders, or trade fairs because the grace period under Section 31 is limited.

Relevant Case Laws

Patent disputes rarely reach the Supreme Court, but a recent survey of its rulings shows that whether claims are clear and fairly based on the specification is among the recurring questions it has settled.19

Novartis AG v. Union of India, (2013) 6 SCC 1:20 The Supreme Court cautioned against a wide gap between what a patent claims and what it discloses. Claims that reach beyond the description are open to attack.

Bishwanath Prasad Radhey Shyam v. Hindustan Metal Industries, (1979) 2 SCC 511:21 The Supreme Court held that combining known elements or making a workshop improvement is not patentable unless it produces something new, useful and non-obvious. This is directly relevant to claims over new arrangements of known filters and tanks.

Farbwerke Hoechst v. Unichem Laboratories, AIR 1969 Bom 255:22 The Bombay High Court held that the specification must describe an embodiment of the invention claimed in each claim, in enough detail for the industry to work it without further invention. This is the basic test for whether alternative versions have been properly supported.

Ferid Allani v. Union of India, 2019 SCC OnLine Del 11867:23 The Delhi High Court held that computer-implemented inventions may be patented where they show a technical effect or technical contribution, supporting a results-focused description of control software.

Syngenta Ltd. v. Controller of Patents and Designs, 2023 LiveLaw (Del) 1029:24 A Division Bench of the Delhi High Court held that a divisional application is maintainable where more than one invention is disclosed in the parent specification, even if not claimed. This rewards detailed specifications.

Practical Implications

For businesses, a patent is only as valuable as the versions it covers. Filing an invention in good form will help to secure protection for the present version, future version, the retrofit and the consumables cartridge, and increase credibility with investors and licensees. The below system roadmap checklist will be helpful when the invention is first disclosed.

1. Components: Discuss at least two options for each main component of your device.

2. Configurations: Show various configurations that can be made with the system, and explain why your configuration goes beyond mere combination of already known parts.

3. Consumables: Discuss replaceable components, such as cartridges and membranes, to claim them individually.

4. Steps and ranges: Indicate which steps should occur in a specific sequence, and indicate general, preferred and precise ranges.

5. Software: Explain how the controls will operate on the actual device, and what advantages they provide.

6. Markets: Consider residential, municipal, and industrial applications, including new facilities and upgrades.

7. Competitors: Name potential work-arounds and discuss them as alternatives.

8. Testing: Present test results, including failures, and the best technique used.

9. Deadlines: File the application before the first disclosure of the invention, and monitor the 12-month period and examination procedure deadlines.

10. Divisions: Label described, but not claimed versions for possible future divisional applications.

From a policy standpoint, the matter hinges on the question of balance. Divisional precedent and the 2025 Guidelines allow applicants more flexibility, but competitors must bear more uncertainty with respect to claims that could be brought against them in the future. With rising public investment in water infrastructure, the shift toward sensors and AI in treatment plants will place section 3(k) under close scrutiny.

Conclusion

Value in water treatment lies within the differences, the next membrane, the improvement package, the disposable cartridge, and the energy-efficient control system. Sections 10, 59 and 64 of the Patents Act make each claim depend on the description originally filed, and thus any variation not mentioned is not protected.

There are three ways to improve things. The Patent Office could include in future editions of its guidelines for computer-related inventions examples taken from industrial process control, which includes water treatment. Divisional filings could have clearer time lines, to alleviate concerns by potential competitors. Finally, awareness campaigns by the Patent Office for small clean technology companies about drafting and provisional filing could prevent those companies from being the most affected by thin descriptions.

Until such changes are made, the principle stated at the beginning of this blog post remains true: The fence can never be larger than the map, so the map needs to be as large and accurate as possible.

Author :- Riya Bhowmik, in case of any query, contact us at Global Patent Filing or write back us via email at support@globalpatentfiling.com.

References

1. ANI, India’s Water Infrastructure Sector Has Opportunities of Rs 1 Lakh Crore: Report, Tribune (Feb. 28, 2025), https://www.tribuneindia.com/news/business/indias-water-infrastructure-sector-has-opportunities-of-rs-1-lakh-crore-report.
2. The Patents Act, 1970, No. 39, Acts of Parliament, 1970 (India).
3. The Patents Act, 1970, § 10(4)–(5) (India).
4. The Patents Act, 1970, § 59(1) (India).
5. The Patents Act, 1970, § 64(1)(h)–(i) (India).
6. The Patents Act, 1970, §§ 48, 104A (India).
7. The Patents Act, 1970, § 3(d)–(f), (k) (India).
8. The Patents Act, 1970, §§ 9, 16, 31 (India).
9. The Patents (Amendment) Rules, 2024, G.S.R. 211(E), Gazette of India (Mar. 15, 2024), r. 13(2A) (India), https://www.ipindia.gov.in/writereaddata/Portal/IPORule/1_83_1_Patent_Amendment_Rule_2024_Gazette_Copy.pdf. 
10. Rahul Kapoor et al., 2024 Amendments to India’s Patent Rules: Unlocking Cross-Border IP Opportunities 2–6 (Morgan Lewis, Oct. 2024), https://www.morganlewis.com/-/media/files/publication/report/2024-amendments-to-indias-patent-rules-unlocking-cross-border-ip-opportunities.pdf. 
11. Off. of the Controller Gen. of Patents, Designs & Trade Marks, Guidelines for Examination of Computer Related Inventions (CRIs) – 2025 (July 29, 2025) (India), https://ipindia.gov.in/writereaddata/images/pdf/CRI/1.%20GUIDELINES%20FOR%20EXAMINATION%20OF%20COMPUTER%20RELATED%20INVENTIONS%20(CRIs)-%202025.pdf. 
12. Devdiscourse News Desk, India Issues Revised 2025 Guidelines for Examining Computer-Related Inventions, Devdiscourse (July 29, 2025), https://www.devdiscourse.com/article/law-order/3521733-india-issues-revised-2025-guidelines-for-examining-computer-related-inventions. 
13. Vikrant Rana & Renu Bala Rampal, Revised CRI Guidelines 2025, Bar & Bench (Apr. 7, 2025), https://www.barandbench.com/law-firms/view-point/revised-cri-guidelines-2025. 
14. Caleb Suresh Motupalli v. Controller of Patents, C.M.A. (PT) No. 2 of 2024 (Madras High Court) (India).
15. Neha Manoria & Shivani Shrivastava, Sufficient Disclosure in Patent Specifications: The India Perspective, Asia IP (Oct. 31, 2020), https://asiaiplaw.com/article/sufficient-disclosure-in-patent-specifications-the-india-perspective. 
16. The Patents Act, 1970, §§ 84–92 (India).