Northern Manufacturing holds the ASME U stamp (Certificate of Authorization #63199) and the ASME PP stamp (Certificate #63198), both authorized May 7, 2026. Code pressure vessels and pressure piping now fabricate in our Oak Harbor, Ohio shop with Hartford Steam Boiler as our Authorized Inspection Agency.
Quality at Northern Manufacturing is not a department — it is embedded in every process, from incoming material verification to final documentation. When software controls physical fabrication and your components enter regulated service environments, a certificate of conformance is not enough. We provide Objective Quality Evidence (OQE) that supports your compliance systems, reduces risk, and protects your business.
ASME U and PP Stamps
ASME issued Northern Manufacturing two Certificates of Authorization on May 7, 2026, both valid through May 7, 2029:
- U stamp, Certificate #63199. Manufacture of pressure vessels at our Oak Harbor, Ohio facility per ASME BPVC Section VIII, Division 1.
- PP stamp, Certificate #63198. Fabrication and assembly of pressure piping at the same facility.
Both certificates authorize shop fabrication at 150 N Lake Winds Parkway in Oak Harbor; field code work is outside their scope. Code jobs run under the same ASME BPVC Section IX welding procedures and 60+ AWS-certified welders as every other Northern job, with our Authorized Inspector from Hartford Steam Boiler (HSB) holding inspection points through fabrication and hydrostatic test. Northern does not hold the R stamp (repairs and alterations) or the S stamp (power boilers).
Quality Management System
Our ISO 9001:2015 certified quality management system governs every fabrication process. This includes document control, traceability, corrective action, and continuous improvement — the framework that ensures consistency across every job, every shift, and every welder.
Key elements of our quality system:
- Document control — work instructions, welding procedures, and inspection plans are controlled and current
- Material traceability — heat number tracking from incoming raw material through finished components, with certified Mill Test Reports (MTRs)
- Process control — qualified welding procedures (WPS/PQR) per ASME BPVC Section IX, with controlled parameters for each material grade
- Corrective action — formal NCR process for nonconformances, with root cause analysis and preventive action
Our Certifications
ASME U and PP stamps. Certificate of Authorization #63199 (U) covers manufacture of pressure vessels and Certificate #63198 (PP) covers fabrication and assembly of pressure piping, both at our Oak Harbor shop. Authorized May 7, 2026, valid through May 7, 2029.
ISO 9001:2015 — Our quality management system is certified to the international standard for quality management. This certification is maintained through regular third-party surveillance audits and covers all fabrication operations.
ASME Section IX welding qualification. Our welding procedures and welder performance qualifications are maintained per ASME BPVC Section IX for the stainless steel and specialty alloy grades we run. Procedure qualification records and welder continuity logs are available on request.
AWS Corporate Member. Our welders hold qualifications per AWS D1.6 (Structural Welding Code, Stainless Steel) and ASME BPVC Section IX, with continuous recertification tracking.
Inspection Capabilities
Our inspection capabilities support both in-process verification and final acceptance:
- Radiographic Testing (RT) — volumetric examination of weld joints for internal discontinuities
- Ultrasonic Testing (UT) — thickness verification and flaw detection in base materials and welds
- Magnetic Particle Testing (MT) — surface and near-surface flaw detection on ferromagnetic materials
- Dye Penetrant Testing (PT) — surface flaw detection on non-ferromagnetic stainless steels and alloys
- Visual Inspection (VT) — trained inspectors examine weld quality, fit-up, and surface condition per AWS and ASME acceptance criteria
- Positive Material Identification (PMI) — handheld XRF analyzers verify elemental composition of incoming materials and finished weldments
Advanced Verification Technologies
We invest in measurement technology that goes beyond traditional inspection:
- Leica Absolute Tracker AT960 + AS1-XL — large-volume 3D metrology for verifying dimensional accuracy on complex assemblies
- FARO laser projectors — CAD-based laser outlines projected onto work surfaces to guide precise placement during assembly
- Servo-Robot WiKi-Scan — non-contact 3D weld scanning that captures fillet size, leg length, throat, and undercut with quantitative, archivable data
Material Traceability
Every piece of stainless steel and specialty alloy that enters our facility is PMI-verified and heat-number tracked. This traceability follows the material through every fabrication step:
- Incoming material verification against MTRs
- In-process PMI at critical weld joints
- Final PMI verification on completed assemblies
- Full documentation packages with MTRs, PMI certificates, weld maps, and dimensional reports