R Stamp #9199 Certification Held as New Manager Leads Tank Specialties

Leadership Change at Tank Specialties Keeps R Stamp Certification and Cargo Tank Services Intact

Fresno, United States – May 10, 2026 / Tank Specialties of California /

Tank Specialties of California has announced the retirement of Darrel Dietz, a longtime manager whose contributions helped establish the company as a dependable resource for cargo tank services, and the promotion of Grayson Cardoza to fill the management role. The transition reflects the company’s continued commitment to certified repair work, regulatory compliance, and consistent service for fleet operators and cargo tank customers.

During his tenure, Dietz played a central role in building the company’s reputation across the Central Valley and surrounding areas. His direction strengthened the technical capabilities and operational consistency that customers in fuel, chemical, agricultural, and transport industries came to rely on.

Cardoza steps into the position with a clear focus on upholding those same standards. His approach prioritizes certified repair services and straightforward guidance on compliance requirements. Tank Specialties continues to function as a single-source provider for cargo tank services, working alongside Advanced Emission to address both cargo tank systems and diesel emissions compliance needs.

Tank Specialties of California maintains its R Stamp #9199 certification, which authorizes the company to perform pressure system repairs in accordance with the National Board Inspection Code (NBIC). This certification is required for repairs and alterations involving pressure-retaining equipment, including cargo tanks used across a range of transport applications.

R Stamp welding ensures that repairs adhere to nationally recognized standards and are supported by proper documentation and inspection oversight. For operators whose equipment must meet regulatory requirements and remain in active service, this level of certification is a practical necessity.

Tank Specialties supports customers with:

Cargo tank inspection and testing
Certified R Stamp pressure system repairs
Tank repair and customization
Compliance support for DOT and safety requirements

Drawing on decades of combined experience and a broad set of in-house capabilities, Tank Specialties serves customers across multiple industries with inspection, repair, fabrication, and compliance-focused services intended to keep equipment operating safely and without interruption.

To learn more about R Stamp welding services or to schedule an assessment, visit tankspecialtiesca.com or call (559) 579-1450.

About Tank Specialties of California: Tank Specialties of California provides cargo tank inspection, repair, and customization services for fleets and operators throughout Fresno, the Central Valley, and surrounding regions. As part of the RV Jensen family of companies, and in partnership with Advanced Emission, the company also supports diesel emissions compliance, Clean Truck Check testing, and related services, offering a comprehensive approach to fleet safety, performance, and regulatory requirements.