
Naturgy is a Spanish multinational energy company with natural gas and electricity operations spanning generation, distribution, and LNG infrastructure across Spain, Latin America, and other international markets. When a project's boilers are ultimately destined for Naturgy-operated or Naturgy-affiliated work, "approved supplier" isn't a marketing phrase — it's a specific, audited status that Naturgy or its EPC contractor grants to individual manufacturers after a formal qualification process. For procurement and engineering teams in Italy sourcing boilers for this kind of work, understanding what that process actually involves is far more useful than searching for a badge.
This article explains what Naturgy-linked vendor approval covers, the engineering baseline it's built on, and what to look for when qualifying a boiler manufacturer for Naturgy-linked or Naturgy-grade projects.
Vendor qualification on Naturgy projects typically involves a detailed audit of a manufacturer's quality management system, welding procedures, material control, non-destructive testing capability, and documented fabrication history. That audit is usually carried out by Naturgy's own engineering and inspection teams, or by a third-party inspection agency acting on its behalf, and the resulting approval is specific to the manufacturer.
Because this status is granted directly by Naturgy to a named manufacturer, it isn't something any supplier can claim without going through that process. What buyers researching suppliers can assess independently — before any formal audit — is whether a manufacturer's engineering and quality practices are already built to the level Naturgy requires.
Regardless of a unit's final destination, the technical requirements that underpin Naturgy-grade fabrication are largely the same requirements that govern quality boiler manufacturing generally:
ASME Section I governs power boiler design, with EN 12952 and EN 12953 as the relevant European reference standards for water-tube and shell boilers respectively, often supplemented with client engineering standards for gas-infrastructure and utility projects.
Full mill test certificates and heat-number traceability carried from raw plate, tube, and forgings through to the finished, assembled boiler.
Drum, tube, and header design engineered for the specified steam or thermal-fluid duty, operating pressure, and temperature.
WPS and PQR documentation, with welders individually qualified under ASME Section IX or EN ISO 9606 as applicable.
Radiographic and ultrasonic testing of pressure-part welds, and magnetic particle or dye penetrant testing on critical joints.
A full pressure test of the assembled boiler, witnessed and documented, before release for shipment.
Hold-point sign-off from an accredited inspection body such as Lloyd's Register, Bureau Veritas, TÜV, or DNV at critical stages of fabrication.
A manufacturer that applies this level of control as standard practice — not only on projects with a named end client — is generally the one positioned to succeed if and when a formal Naturgy audit takes place.
Notdstone manufactures customized process equipment for the oil, gas, and process industries, serving Italy, the GCC, and international markets, with more than three decades of engineering experience across the team. Our fabrication and QA/QC processes are structured around the technical baseline described above — documented material traceability, ASME IX-qualified welding, comprehensive NDT, and hydrostatic testing before delivery.
To be clear with buyers researching this topic: formal vendor approval with Naturgy is issued directly by Naturgy to specific manufacturers following its own audit process, and we're not claiming that status here. What we can speak to with confidence is the engineering rigor our boilers are built to on every project.
Steam and thermal-fluid boilers engineered for reliable, code-compliant thermal generation.
ASME Section VIII-compliant vessels engineered for safe containment under demanding pressure and temperature conditions.
TEMA-designed shell-and-tube units for heating, cooling, condensation, and energy recovery.
API 650/620-referenced tanks for liquids, gases, chemicals, and petroleum products.
Distillation, absorption, and stripping columns engineered for process efficiency in chemical and petrochemical service.
Factory-assembled modular skids integrating vessels, pumps, piping, and instrumentation to compress site installation time.
It means the manufacturer has been formally audited and accepted by Naturgy, covering their quality system, welding procedures, and testing capability for boiler fabrication.
ASME Section I is a common reference code for power boilers, with EN 12952 and EN 12953 as the relevant European standards, often supplemented with Naturgy's own engineering standards.
For high-pressure steam service or corrosive fuel gas, yes — alloy steel pressure parts or corrosion-resistant tube materials may be specified instead of standard carbon steel.
Yes, provided their code compliance, material traceability, and third-party inspection arrangements meet the project specification and export logistics support delivery of the finished unit.
Ask for written confirmation of the approval status and its exact scope — which equipment categories it covers — rather than relying on a general claim.
If your project requires boilers engineered to recognized pressure-part codes and manufactured under documented quality control, our engineering team can review your process requirements and provide a project-specific proposal. Get in touch with Notdstone to discuss your requirements.