Form SD Enerflex Ltd.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM SD

SPECIALIZED DISCLOSURE REPORT

ENERFLEX LTD.

(Exact name of registrant as specified in its charter)

Suite 904, 1331 Macleod Trail S.E.

Calgary, Alberta, Canada, T2G 0K3

(Address of Principal Executive Offices) (Zip Code)

Steven Smart (281) 855-5137

(Name and telephone number, including area code, of the person to contact in connection with this report.)

Check the appropriate box to indicate the rule pursuant to which this form is being filed, and provide the period to which the information in this form applies:

☒ Rule 13p-1 under the Securities Exchange Act (17 CFR 240.13p-1) for the reporting period from January 1 to December 31, 2025.

Section 1 - Conflict Minerals Disclosure

Enerflex Ltd. (“Enerflex”, the “Company”, “we”, “us”, “our”) is a leading provider of modular natural gas, power technology and treated water solutions, delivering value through disciplined execution and a deliberate approach to where we compete. Our customer focused delivery model supports operational excellence, innovation, and scalability across our global footprint with a focus on creating long-term shareholder value. Headquartered in Calgary, Alberta, Canada, with approximately 4,400 engineers, manufacturers, technicians, professionals, and innovators, Enerflex is bound together by a shared vision: Transforming Energy for a Sustainable Future. The Company remains committed to the future of natural gas and the critical role it plays, while focused on sustainability offerings to support the world’s energy needs. Enerflex has operations in 17 countries across North America, Latin America, and the Eastern Hemisphere, including in its core operating countries, the United States (the USA), Canada, Oman, Bahrain, Argentina, Brazil, and Mexico. With over 700,000 sq. ft. of manufacturing capability in three fabrication facilities across North America, Enerflex delivers high-quality, long-life solutions globally.

As part of our business, we manufacture products for which gold, tantalum, tin and/or tungsten (collectively, “3TG materials”) are necessary to the functionality or production of our products. We are required to comply with Rule 13p-1 of the Securities Exchange Act of 1934, as amended, as implemented through SEC Specialized Disclosure Report on Form SD (“Rule 13p-1”). Accordingly, in compliance with Rule 13p-1, we are filing this Specialized Disclosure Report on Form SD and the Conflict Minerals Report filed as Exhibit 1.01 hereto, and have contemporaneously posted this Specialized Disclosure Report on Form SD and the Conflict Minerals Report on our website at www.enerflex.com.

A copy of Enerflex Ltd.’s Conflict Minerals Report for the reporting period January 1, 2025 to December 31, 2025 is provided as Exhibit 1.01 hereto and is publicly available on our website at www.enerflex.com.

The Conflict Minerals Report required by Item 1.01 is filed as Exhibit 1.01 to this Form SD.

Section 2 – Exhibits

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the duly authorized undersigned.