Welding & Fabrication Services

Project Management & Planning

Fabrication, Installation, & Other Field Services

Manual, Semi-Automatic, & Machine Welding

Large Component Removal & Replacement

Welder Qualifications & Training

First-of-a-Kind (FOAK) & Mock-up Services

Bringing Big Ideas to Life

Industries at the forefront of discovery, face many unique challenges getting projects off the ground. For more than a century, forward-thinking companies on the leading edge of innovation have trusted Day & Zimmermann to meet their highest expectations for safety, quality, and precision and help them bring big ideas to life.

We deliver safe, high-quality, and predictable performance from concept development and engineering to prefabrication and installation to preventative maintenance using our QA/QC accredited programs.

Our Tennessee, North Carolina, and Arizona fabrication shops are outfitted with the latest technology and equipment to meet most project requirements.

  • ASME Pressure Vessel Fabrication and National Board Inspection Code (NBIC) - Repair
  • Concept-to-creation Fabrication
  • Planning and Mock-up Services
  • Final Testing and Acceptance
  • Structural Steel Platforms, Mezzanines, & Stairs
  • High-Purity Piping Fabrication and Installation
  • Sanitary Process Piping

We can simulate clean room conditions including setups for limited access and complex configuration welds.

Our welding and fabrication team strictly adheres to code requirements and hold-point verification, using informational non-destructive examination (NDE) and supervisor training to maintain the highest performance.

Training & Workforce Development

UA Welder Certification Program

Construction Users Round Table (CURT)

Helmets to Hardhats (for military service members)

State-level building trades groups

Machining & Other Services


Field and shop end-prep piping and tubing materials

Feedwater heater cutouts

Flange facing

Hole boring

Qualified machining personnel

Full Non-destructive Examination (NDE)

Post Weld Heat Treat (PWHT)

Quality Processes, Procedures, & Certifications

ASME Section IX

S Stamp, U Stamp, NBIC "R" Stamp

10 CFR Appendix B

“My company has worked with D&Z Welding Services for the past three years as a partner on numerous projects, and I look forward to working with them again for future plant modifications. The company offers high-quality service, and I have been more than satisfied by their work and leadership.”

Framatome Project Manager at Palo Verde Nuclear Generating Station

Our Success




Weld Reject Rate


Years of Welding Expertise


Projects Completed

Industries We Serve


Process & Industrial

Pulp & Paper

Liquefied Natural Gas





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