
Heirs Oil & Gas is one of Nigeria’s fast-growing indigenous energy companies, with upstream production and midstream infrastructure interests including onshore and shallow-water assets in the Niger Delta. When a project’s process skids are ultimately destined for a Heirs Oil & Gas facility, “approved supplier” isn’t a marketing phrase — it’s a specific, audited status the client grants to individual manufacturers after a formal qualification process. For procurement and engineering teams in Italy sourcing process skids for this kind of work, understanding what that process actually involves is far more useful than searching for a badge.
This article explains what Heirs Oil & Gas vendor approval covers, the engineering baseline it’s built on, and what to look for when qualifying a process skid manufacturer for Heirs Oil & Gas-linked or -grade projects.
Heirs Oil & Gas maintains its own vendor qualification process, which involves a detailed review of a manufacturer’s quality management system, welding and piping fabrication procedures, material control, non-destructive testing capability, and documented fabrication history. That review is typically carried out by the client’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 and the equipment category involved.
Because this status is granted directly by Heirs Oil & Gas 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 Heirs Oil & Gas requires.
Regardless of a process skid’s final destination, the technical requirements that underpin Heirs Oil & Gas-grade fabrication are largely the same requirements that govern quality modular skid manufacturing generally, with the added considerations typical of onshore and shallow-water upstream production:
ASME B31.3 governs the process piping on the skid, ASME Section VIII applies to any pressure vessels or drums mounted on it, and structural steelwork follows recognized structural design codes, with client engineering standards layered on top for upstream production projects.
Full mill test certificates and heat-number traceability carried from raw plate, pipe, and structural steel through to the finished, assembled skid, including sour-service material certification where required.
Design that accounts for skid lifting and transport loads, piping stress analysis, equipment layout, and instrumentation and electrical routing, verified through calculation packages and, where required, finite element analysis.
WPS and PQR documentation for both structural and piping welds, with welders individually qualified under ASME Section IX.
Radiographic or ultrasonic testing of piping and vessel welds, along with magnetic particle and dye penetrant testing of structural attachments and nozzles.
A full pressure test of piping and any mounted pressure vessels, plus functional testing of instrumentation, controls, and rotating equipment before the skid leaves the shop.
Hold-point sign-off from an accredited inspection body such as Lloyd’s Register, Bureau Veritas, TÜV, or DNV at critical stages of fabrication and assembly.
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 Heirs Oil & Gas audit takes place.
Notdstone manufactures factory-assembled process skids integrating vessels, pumps, piping, and instrumentation for demanding oil and gas processing applications, 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 and functional testing before delivery.
To be clear with buyers researching this topic: formal vendor approval with Heirs Oil & Gas is issued directly by Heirs Oil & Gas to specific manufacturers following its own review process, and we’re not claiming that status here. What we can speak to with confidence is the engineering rigor our process skids are built to on every project. Our process skid fabrication work follows this same baseline, whether or not a project names a specific end client.
It means the manufacturer has been formally reviewed and accepted by Heirs Oil & Gas, covering their quality system, welding and piping procedures, and testing capability for skid fabrication.
ASME B31.3 governs the process piping, ASME Section VIII applies to any mounted pressure vessels, and structural steelwork follows recognized structural codes, often supplemented with the client’s own engineering standards.
For sour service, high-pressure processing, or corrosive production streams, yes — corrosion-resistant piping, coatings, or instrumentation ratings may be specified instead of standard carbon steel components.
Yes, provided their code compliance, material traceability, and third-party inspection arrangements meet the project specification and export logistics support delivery and installation of the skid.
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 process skids engineered to ASME standards 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.


