PED CE Steam Generator for Turkey: How Lmart Delivered Inconel 825 Pressure Vessels Across Borders
By Qiangbin Chu · Sales Manager & Operations Lead
A Shell-and-Tube Steam Generator Built to EU Pressure Equipment Directive Standards for Industrial Gas Application in the Turkish Metals Sector
| End Customer | Air Products |
| End User / Plant | Tatmetal (Turkish metals & steel processing) |
| Project Name | Tatmetal Project |
| Location | Turkey |
| Equipment | 1× Steam Generator |
| Dimensions | DN762 × THK10 × L2285 mm |
| Shipping Weight | 1,560 kg |
| Shell Material | SB424 N08825 (Inconel 825) / Duplex 2205 |
| Tube Material | N08825 (Inconel 825) |
| Design Standard | PED 2014/68/EU — CE Marking Required |
| Application | Industrial gas for metals processing |
| Lmart Role | PED-certified manufacturer, full CE documentation |
Customer Background: Air Products and the Turkish Industrial Gas Market
Air Products is one of the world’s largest industrial gas companies, operating in more than 50 countries and supplying hydrogen, nitrogen, oxygen, argon, and specialty gases to some of the most demanding process industries on earth. Their supply chain demands are uncompromising — equipment must be code-compliant, reliably documented, and ready for operation in the hands of a licensed end user.
Tatmetal is that end user: a Turkish metals and steel processing company that depends on a continuous supply of industrial gas to run its production lines. Steel and metals processing is Turkey’s industrial backbone. Turkey is the eighth-largest steel producer globally, and companies like Tatmetal operate under European-aligned technical standards — which means pressure equipment entering the plant must carry the CE mark under the EU Pressure Equipment Directive (PED 2014/68/EU).
For Air Products, qualifying a supplier outside Europe for PED-certified steam generators is not a decision taken lightly. The equipment must be manufactured under a quality system approved by a Notified Body, every weld and material must be traceable, and the final product must carry a legitimate CE mark — not a sticker, but a certification earned through audited design, manufacture, and testing.
The challenge was finding a Chinese manufacturer with genuine PED capability, not just an ASME shop willing to add a CE label.
The Challenge: PED CE Compliance Is Not the Same as ASME
Most engineers in the West assume Chinese pressure vessel manufacturers work exclusively to ASME standards. That assumption is correct for the majority of the market — but it creates a real procurement gap when the destination country requires CE marking.
PED 2014/68/EU operates on entirely different principles from ASME VIII:
- Risk-based classification: PED classifies equipment into Categories I through IV based on fluid hazard group and operating parameters. Higher categories require more rigorous third-party involvement.
- Notified Body (NB): A European-approved inspection body must be formally appointed. For Category III and IV equipment, the NB witnesses key fabrication stages — hydrotesting, NDE, final inspection — and co-signs the technical file.
- Essential Safety Requirements (ESRs): The manufacturer must demonstrate compliance with ESRs covering design, materials, fabrication, and testing — not just meet a pressure calculation standard.
- Technical File: A complete dossier — design calculations, material traceability, WPS/PQR records, NDE reports, NB witness certificates, and a Declaration of Conformity — must be compiled and retained.
- CE Marking: Only after NB approval can the equipment be CE-marked and released to the market. The mark is legally binding in EU-adjacent markets including Turkey under the Turkey-EU Customs Union.
For Air Products’ procurement team, the concern was straightforward: could a Chinese manufacturer navigate this process without procedural gaps that would surface during Tatmetal’s incoming inspection or a future regulatory audit?
Why Lmart: Dual ASME + PED Certification Under One Roof
Lmart holds both ASME U-stamp and PED 2014/68/EU certification. This is not a common combination. ASME certification requires a joint review by ASME and the National Board; PED certification requires a European Notified Body audit of the quality management system and periodic surveillance. Operating both in parallel means maintaining two separate quality systems that are internally consistent — a significant administrative and engineering commitment.
For Air Products, this dual certification resolved the core qualification question immediately. Lmart was not a general fabricator attempting PED work for the first time. The quality system had already been audited. The procedures for NB coordination, technical file compilation, and CE marking were established and rehearsed.
Beyond certification, several factors made Lmart the right fit for the Tatmetal project:
- Inconel 825 and Duplex 2205 fabrication experience: Exotic alloy work requires weld procedure qualifications (WPS/PQR) specific to those materials. Lmart had existing qualifications covering N08825 and Duplex 2205.
- PED design calculation capability: Lmart’s engineering team performs PED pressure calculations in-house, reducing iteration cycles with the NB.
- English-language documentation: Full technical file deliverables in English, formatted to NB requirements — no translation layer, no misinterpretation risk.
- Export logistics familiarity: Lmart regularly ships to the Middle East and Europe. Export packing, ISPM-15 compliance, and CIF/CFR documentation are standard deliverables.
Engineering Solution: Inconel 825 Shell, N08825 Tubes, PED Design Basis
The steam generator’s service conditions drove the material selection. Industrial gas processing in metals and steel applications can involve corrosive process streams — sulfuric acid, chlorides, and elevated temperatures that would rapidly degrade carbon steel or even standard stainless. Inconel 825 (UNS N08825) was specified for both shell and tubes because of its outstanding resistance to pitting, crevice corrosion, and stress corrosion cracking in acidic and chloride-bearing environments.
Shell construction used SB424 N08825 plate for the primary shell body, with Duplex 2205 selected for specific structural components where the combination of high strength and corrosion resistance offered a weight and cost advantage without compromising service life.
Tube bundle: All tubes were fabricated from N08825 seamless tube material, fully traceable to mill certificates with chemical and mechanical properties conforming to ASTM/ASME material specifications.
PED design calculations were performed to EN 13445 (Unfired Pressure Vessels) by Lmart’s engineering team. The design covered:
- Maximum allowable working pressure (MAWP) at operating temperature
- Shell and tube-sheet thickness calculations per PED essential safety requirements
- Nozzle reinforcement analysis
- Fatigue assessment where applicable under PED Category classification
The Notified Body reviewed and accepted the design calculations as part of the technical file prior to fabrication release.
Why Inconel 825? Material Selection Rationale
| Property | 316L SS | Inconel 825 (N08825) | Inconel 625 (N06625) |
|---|---|---|---|
| SCC Resistance | Poor — fails in chloride environments | Excellent | Superior |
| Pitting Resistance (PREN) | ~25 | ~33 | ~51 |
| Max Service Temp | ~450 °C | ~540 °C | ~650 °C |
| Weldability | Excellent | Good — requires qualified WPS | Good — requires qualified WPS |
| Relative Material Cost | 1× | 3–4× | 6–8× |
| Typical Application | General chemical service | H&sub2;/syngas, high-purity gas, sulfuric acid | Subsea, ultra-high corrosion |
For this service — high-purity hydrogen generation with mixed acid condensate — Inconel 825 provides the required corrosion resistance at roughly half the cost of Inconel 625, making it the engineering-optimal choice.
Quality Control and the PED Documentation Trail
PED compliance is built into manufacturing — it cannot be added after the fact. For the Tatmetal steam generator, quality milestones were aligned with the Notified Body witness plan from day one.
Material Traceability: All N08825 and Duplex 2205 materials were received with 3.1 or 3.2 mill test certificates as required by the NB. Each plate and tube coil was individually numbered and tracked through fabrication.
Welding: Weld procedures (WPS) and procedure qualification records (PQR) specific to N08825 and Duplex 2205 dissimilar and similar metal joints were on file. All welders were qualified under the applicable WPS. Weld maps tied every joint back to a qualified WPS and a qualified welder.
NDE: Non-destructive examination was performed per the PED-required inspection plan — radiographic testing (RT) of butt welds and liquid penetrant testing (PT) of fillet welds and attachment welds, with reports issued under EN standards.
NB Witness Points: The appointed Notified Body held witness points at hydrostatic testing and final visual/dimensional inspection. NB certificates were issued and incorporated into the technical file.
CE Marking and Declaration of Conformity: Upon successful completion of all witness points and NDE, Lmart issued the CE Declaration of Conformity, affixed the CE mark with the NB identification number, and compiled the complete technical file for handover to Air Products.
Delivery: The steam generator was hydrotested, preserved, and packed in a custom export crate with internal blocking to protect nozzle faces and instrumentation connections. Shipping weight: 1,560 kg. All export documents — commercial invoice, packing list, certificate of origin, test certificates, CE declaration — were prepared in English.
Results
The Tatmetal steam generator was delivered on schedule and passed Tatmetal’s incoming inspection without a single corrective action request. Air Products’ procurement team received a complete, audit-ready technical file that satisfied both their internal quality standards and Turkey’s regulatory requirements under the EU-Turkey Customs Union alignment.
Key outcomes:
- Full PED CE compliance with Notified Body witness certificates and Declaration of Conformity
- Zero NCRs on incoming inspection at the Turkish end-user facility
- Complete technical file handed over in English, audit-ready
- On-time delivery within the contracted lead time for a single custom-fabricated exotic alloy vessel
- Material traceability from mill certificate to finished weld — every joint accountable
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Customer Voice
Air Products selected Lmart for this project based on demonstrated capability and placed the order through a competitive qualification process — the strongest form of supplier endorsement in capital equipment procurement.
“We’ve qualified Chinese manufacturers for ASME work before, but PED is a different conversation. Lmart had the certifications, the NB relationship, and the documentation discipline we needed. The technical file they delivered was cleaner than what we sometimes get from European shops. We’ll be going back to them for the next project.”
— **Procurement Manager, Air Products** (paraphrased from project review feedback)
Note: Lmart respects client confidentiality. Specific contact references are available upon request during the qualification process.