National Board R-Stamp
R-Stamp welding done to code. Documented. Defensible.
Pressure vessel repair on petroleum transport tanks performed by R-Stamp certified welders. Done to ASME and National Board standards. Documented for terminal compliance and DOT inspection.
R-Stamp is the National Board certification for repair and alteration of pressure-retaining items. For petroleum tank trailers, R-Stamp work isn't optional. If your tank has been compromised — cracks, gouges, weld defects, structural failures — the repair has to be performed by a certified shop, documented per code, and reported per National Board requirements. Post Onsite holds active R-Stamp certification. We do this work every week.
R-Stamp work we perform
Shell crack repair
Cracks in the tank shell repaired per R1 and ASME Section IX procedures. NDT (non-destructive testing) performed before and after. Documentation per National Board Code.
Bulkhead and head repair
Front and rear bulkhead repairs, dished head repairs, including structural reinforcement and full plate replacement when required.
Manhole and dome cover work
Manhole assembly repair and replacement, dome cover sealing surfaces, gasket landing repair. All work performed to ASME and DOT requirements.
Internal valve and outlet repair
Internal valve mounting plate repair, emergency valve assembly repair, bottom-loading and top-loading fitting work.
Compartment baffle and bulkhead
Inter-compartment baffles, internal bulkhead repair, compartment-to-compartment leak corrections.
Documentation & National Board reporting
Every R-Stamp repair generates an R-1 form. Filed with the National Board. Copy retained for your records and provided to your insurance and terminal compliance teams.
Schedule the work or request an assessment.
Mon–Fri 7am–6pm. Emergency response 24/7.
What good R-Stamp work looks like
When you bring a tank to Post Onsite, here's what you should expect.
- Pre-weld inspection with documentation of the defect
- NDT before any cutting begins
- Welding performed by R-Stamp certified welder with WPS documentation
- NDT after weld completion (typically magnetic particle or dye penetrant)
- Pressure or leak test as required by code
- R-1 form completed, signed, and filed with the National Board
- Copy of all documentation provided to fleet operator
Why fleets bring R-Stamp work to Post Onsite
R-Stamp work is specialty work. Most general trailer shops can't perform it because they don't hold the certification. Of the shops that do hold it, most don't do enough volume to keep their welders current and their procedures sharp. Post Onsite does R-Stamp work every week — sometimes multiple jobs in a day. The certification stays active and the work stays clean.
We document everything. We've watched fleet customers get hassled by terminal compliance auditors and DOT inspectors over previous welds where the paperwork was missing or inadequate. Our R-1 forms are complete, defensible, and provided to you the day the work is finished. If a compliance question comes up six months later, the documentation is in your records and ours.
Common questions
What's the difference between R-Stamp and regular welding?
Regular welding doesn't have third-party certification or required documentation. R-Stamp work is performed under a National Board certification, follows specific Welding Procedure Specifications (WPS), is documented on an R-1 form, and is reported to the National Board. For pressure vessels — which tank trailers are — R-Stamp is the requirement, not the option.
How long does R-Stamp work take?
Depends entirely on the scope. Simple shell crack repair with documentation can be 1-2 days. Larger work like bulkhead replacement or multi-compartment repair can be 3-7 days. We give you a real timeline at quote, including the testing and documentation steps.
Will the R-1 form be filed with the National Board?
Yes. Every R-Stamp repair we perform results in a filed R-1. You receive a copy. The original is filed with the National Board per code requirements.
Can you do R-Stamp work mobile?
Some R-Stamp work can be performed at your facility along the I-40 and I-75 corridors if conditions allow safe welding and adequate inspection environment. Most R-Stamp work is better performed in-shop where lighting, ventilation, and NDT equipment are controlled. We'll tell you which makes sense for your specific repair.
Related services
Tank Remounts
Full tank remounts — removing your existing petroleum tank from an aging chassis, inspecting it, and mounting it on a new trailer. R-stamp certified, documented, defensible.
Learn more →DOT Tank Testing
Annual external visual, periodic internal inspection, pressure testing, and lining inspection performed per 49 CFR 180.407. Documentation that survives the audit.
Learn more →Barrel Repair
Structural and barrel repair to petroleum tank trailers. Damage from incidents, corrosion, impact, or routine wear. R-stamp work performed where required, documented per code.
Learn more →Get the work scheduled.
Same-week appointments most weeks for fleet customers. Emergency response 24/7. Call or request an assessment and we'll get you scheduled.