14.4 Tank Marking, Nameplates, Inspection Reports & Recordkeeping (API 653 Section 13)

Statutory Triggers for API 653 Nameplate Installation

Under API Standard 653 Section 13, the physical marking and stamping of an aboveground atmospheric storage tank is a statutory legal requirement that certifies compliance with industry safety standards. The original nameplate installed at the time of construction under API Standard 650 (or predecessor standards such as API 12C) documents the baseline as-built design envelope. However, as tanks endure decades of service, undergo physical repairs, or are re-engineered for different operating products, their mechanical ratings evolve.

To ensure operating personnel, local code jurisdictions, and regulatory inspectors have unambiguous visibility into the current structural rating of the vessel, API 653 mandates the installation of an official API 653 Nameplate under four specific conditions:

+-------------------------------------------------------------------------+
|             MANDATORY TRIGGERS FOR API 653 NAMEPLATE (SECTION 13)      |
|                                                                         |
|   +-----------------------------------------------------------------+   |
|   | 1. TANK RECONSTRUCTION                                          |   |
|   |    Tank dismantled, relocated, and re-erected per Section 10    |   |
|   +-----------------------------------------------------------------+   |
|   | 2. TANK ALTERATION                                              |   |
|   |    Physical changes affecting structural / pressure boundary    |   |
|   +-----------------------------------------------------------------+   |
|   | 3. OPERATIONAL RE-RATING                                        |   |
|   |    Changes in Maximum Liquid Level (H), Specific Gravity (G),   |   |
|   |    or Maximum Design Operating Temperature                      |   |
|   +-----------------------------------------------------------------+   |
|   | 4. MAJOR REPAIR WITH DESIGN RE-VERIFICATION                     |   |
|   |    Extensive shell course replacement or structural re-design   |   |
|   +-----------------------------------------------------------------+   |
+-------------------------------------------------------------------------+

Clarification: Routine Maintenance vs. Nameplate Triggers

• Routine Repairs Do Not Trigger a Nameplate: Standard maintenance activities—such as installing a lapped patch plate on a bottom sketch plate outside the Critical Zone, performing a localized weld overlay on pitting, or replacing a corroded roof rafter—do not require an API 653 nameplate. Routine repairs maintain baseline suitability without modifying the design envelope.
• Mandatory Re-Rating Trigger: If a terminal operator increases the maximum fill height ($H$) of a tank by adjusting high-level alarm switches, or increases the permissible specific gravity ($G$) of stored fluid from $0.82$ to $0.95$ (increasing hydrostatic hoop stress $S = 2.6 D H G / t$), an API 653 nameplate must be installed reflecting the recalculated operational envelope.

Required Nameplate Data Items and Stamping Specifications

API Standard 653 Figure 13.1 establishes the standardized format and data schema that must be permanently stamped onto the API 653 nameplate.

+-------------------------------------------------------------------------+
|                    API STANDARD 653 CERTIFICATION NAMEPLATE             |
|                                                                         |
|   +-----------------------------------------------------------------+   |
|   |                    API STANDARD 653                             |   |
|   | EDITION / ADDENDUM: 5th Edition, Addendum 2                     |   |
|   | YEAR COMPLETED: 2026                                            |   |
|   | REPAIR / ALTERATION ORGANIZATION: Gulf Coast Tank Services LLC  |   |
|   | TANK IDENTIFICATION NO.: TK-401-CRUDE                           |   |
|   +-----------------------------------------------------------------+   |
|   | MAXIMUM DESIGN LIQUID LEVEL (H): 46.5 FT (14.17 M)              |   |
|   | MAXIMUM SPECIFIC GRAVITY (G): 0.88                              |   |
|   | MAXIMUM DESIGN TEMPERATURE: 140°F (60°C)                        |   |
|   | MINIMUM DESIGN METAL TEMP (MDMT): -15°F (-26°C)                 |   |
|   | SHELL JOINT EFFICIENCY (E): 0.85                                |   |
|   +-----------------------------------------------------------------+   |
|   | SCOPE / SUMMARY OF WORK:                                        |   |
|   | REPLACED LOWEST SHELL COURSE PLATE; INSTALLED NPS 24 SHELL      |   |
|   | MANWAY; RE-RATED FILL HEIGHT PER SECTION 9 & 12                |   |
|   +-----------------------------------------------------------------+   |
+-------------------------------------------------------------------------+

Mandatory Nameplate Fields (Section 13.1.1)

The nameplate must contain the following information stamped in letters and numerals not less than $5/32\text{ in.}$ ($4\text{ mm}$) high:

1. Standard Designation: "API STANDARD 653".
2. Edition and Addendum Number: The specific revision of API 653 in effect when the work was completed.
3. Year Completed: The calendar year in which the reconstruction, alteration, or re-rating was certified.
4. Repair/Alteration Organization: The legal corporate name of the certified contractor or owner-user maintenance organization that performed the work.
5. Tank Identification Number: The owner-user facility asset tag number (or original manufacturer's serial number).
6. Maximum Design Liquid Level ($H$): The certified maximum operating liquid height in feet (or meters).
7. Maximum Design Specific Gravity ($G$): The maximum allowable specific gravity of stored product.
8. Maximum Design Temperature: Maximum operating temperature in °F (or °C).
9. Minimum Design Metal Temperature (MDMT): The lowest permissible operating metal temperature in °F (or °C) established per Section 5 to prevent catastrophic brittle fracture.
10. Shell Joint Efficiency ($E$): The weld joint efficiency factor ($0.70$, $0.85$, or $1.00$) utilized in the minimum shell thickness calculations.

Nameplate Fabrication, Attachment & Physical Marking Protocols

To ensure the nameplate survives decades of harsh marine, refining, and industrial atmospheric exposure, API 653 Section 13 establishes strict metallurgical and mechanical attachment protocols.

+-------------------------------------------------------------------------+
|                   NAMEPLATE ATTACHMENT CONFIGURATIONS                   |
|                                                                         |
|   METHOD A: DIRECT SHELL ATTACHMENT     METHOD B: STANDOFF BRACKET      |
|                                                                         |
|        Tank Shell Plate                      Tank Shell Plate           |
|         |                                     |                         |
|         |  Continuous Perimeter               |  Continuous Seal Weld   |
|         |  Seal Weld (No Crevice)             |  ====================   |
|         |  +--------------------+             |  | Standoff Bracket |   |
|         |==|   NAMEPLATE        |             +--+                  +-- |
|         |  |   (Stainless/      |                |                  |   |
|         |  |    Monel)          |                +------------------+   |
|         |==+--------------------+                     o        o        |
|         |                                      Stainless Steel Fasteners|
|         |                                      & Nameplate Face         |
+-------------------------------------------------------------------------+

Metallurgy and Material Specifications

• Corrosion-Resistant Metal: Nameplates must be fabricated from austenitic stainless steel (e.g., AISI Type 304 or 316) or Monel alloy. Carbon steel, galvanized sheet, or brass nameplates are strictly prohibited due to corrosion degradation.
• Minimum Thickness: Nameplates must possess sufficient mechanical rigidity to prevent distortion during stamping and welding, typically maintaining a minimum nominal thickness of $3/64\text{ in.}$ ($1.2\text{ mm}$).

Attachment Protocols (Section 13.2)

1. Direct Shell Attachment: The nameplate is positioned directly on the tank shell adjacent to the original API 650 manufacturer's nameplate. It must be continuously seal-welded around its entire outer perimeter using compatible stainless steel welding electrodes (e.g., AWS E309L for attaching stainless steel to carbon steel shell). Continuous seal-welding is mandatory to prevent moisture ingress behind the plate, which creates aggressive crevice corrosion.
2. Standoff Bracket Attachment: Where tanks are externally insulated, direct shell mounting would conceal the nameplate beneath jacketing. In such cases, the nameplate is mounted to a sturdy steel standoff bracket that extends through the insulation cladding, positioning the nameplate clearly visible on the exterior skin. The bracket must be continuously seal-welded to the shell, and the nameplate attached using tamper-resistant stainless steel rivets or tack welds.
3. Location and Accessibility: Nameplates must be located on the lowest shell course immediately adjacent to a primary shell manway, at an elevation of $3\text{ to }5\text{ feet}$ ($1.0\text{ to }1.5\text{ meters}$) above grade to enable direct visual inspection without specialized climbing equipment.

API 653 Formal Inspection Reports (Section 6.9)

Under API 653 Section 6.9, a comprehensive written inspection report must be prepared and certified following every formal in-service external inspection, out-of-service internal turnaround inspection, or major repair/alteration.

+-------------------------------------------------------------------------+
|                 MANDATORY REPORT SECTIONS PER API 653 6.9               |
|                                                                         |
|   +-----------------------------------------------------------------+   |
|   | 1. ADMINISTRATIVE & CERTIFICATION CREDENTIALS                   |   |
|   |    Dates of inspection, facility, Authorized Inspector ID       |   |
|   +-----------------------------------------------------------------+   |
|   | 2. SCOPE OF INSPECTION & COMPONENT INVENTORY                    |   |
|   |    Visual VT, UT scans, settlement, MFL floor survey            |   |
|   +-----------------------------------------------------------------+   |
|   | 3. QUANTITATIVE NDE DATA & THICKNESS MEASUREMENTS               |   |
|   |    Actual thicknesses (t_act), corrosion rates (r), RCA         |   |
|   +-----------------------------------------------------------------+   |
|   | 4. STRUCTURAL INTEGRITY & LIFE PROJECTION CALCULATIONS          |   |
|   |    Shell t_min, bottom MRT, roof structural capacity           |   |
|   +-----------------------------------------------------------------+   |
|   | 5. FOUNDATION SETTLEMENT ANALYSIS                               |   |
|   |    Survey raw data, fitted cosine curve, S_max comparison       |   |
|   +-----------------------------------------------------------------+   |
|   | 6. PRIORITIZED REPAIR RECOMMENDATIONS & NEXT INTERVAL           |   |
|   |    Action items, mandatory hold points, return-to-service date  |   |
|   +-----------------------------------------------------------------+   |
+-------------------------------------------------------------------------+

Mandatory Inspection Report Contents

A complete inspection dossier must compile all empirical findings into a legally defensible engineering package:

1. Inspector Identification: Full name, employer, and the active API 653 Certification Number of the Authorized Inspector.
2. Inspection Dates: Dates when field physical examinations were performed and formal report issuance date.
3. Detailed Scope Description: Clear delineation of inspection boundaries (e.g., complete internal floor MFL, shell crawler UT, floating roof seal gap audit, fixed roof structure visual).
4. Visual Examination Findings: Comprehensive visual documentation of metal loss, distortion, weld undercut, coating breakdown, cathodic protection anode condition, and mechanical wear.
5. Quantitative NDE Data Sheets: Ultrasonic thickness readings tabulated by shell course, bottom sketch plate grids, nozzle necks, and roof plates.
6. Corrosion Rate & Remaining Life Calculations: Formal calculation of short-term and long-term corrosion rates ($r$), Remaining Corrosion Allowance ($RCA$), and projected remaining life for shell, roof, and floor.
7. Settlement Survey Dossier: Circumferential elevation readings, graphic cosine curve plot, edge settlement profiles, and verification against $S_{\max}$ and Annex B criteria.
8. Prioritized Remedial Recommendations: Clear list of mandatory repairs required before return to service, along with non-critical recommendations for future turnarounds.
9. Next Inspection Interval: Formally designated date for the next routine in-service inspection, external UT survey, and out-of-service internal inspection per Section 6.
10. Official Inspector Signature: Formal return-to-service certification signed and stamped by the API 653 Authorized Inspector.

Owner-User Recordkeeping Obligations (Section 6.8)

API Standard 653 Section 6.8 establishes strict statutory recordkeeping mandates for tank owner-users. Because aboveground storage tanks represent high-consequence containment assets operating over 50 to 100-year lifecycles, maintenance of comprehensive asset documentation is vital to public safety and environmental compliance.

API 653 establishes a fundamental legal division between two distinct classes of records:

+-------------------------------------------------------------------------+
|               API 653 RECORDKEEPING ARCHITECTURE (SECTION 6.8)          |
|                                                                         |
|   +------------------------------------+----------------------------+   |
|   | PERMANENT RECORDS                  | PROGRESSIVE RECORDS        |   |
|   | (Retained for Tank Lifetime)       | (Retained Over Cycles)     |   |
|   +------------------------------------+----------------------------+   |
|   | - Original Construction Drawings   | - Routine In-Service Logs  |   |
|   | - Design Calculations & Reratings  | - External UT Reports      |   |
|   | - Mill Test Reports (MTRs)         | - Out-of-Service Reports   |   |
|   | - Baseline As-Built Inspection     | - CP Survey Potential Logs |   |
|   | - Alteration / Reconstruction Logs | - Settlement Survey History|   |
|   | - Hydrotest Exemption Dossiers     | - Routine Repair Records   |   |
|   | - WPS, PQR & Welder Certifications | - Internal Lining Audits   |   |
|   +------------------------------------+----------------------------+   |
+-------------------------------------------------------------------------+

1. Permanent Records (Lifetime Retention)

Permanent records must be securely archived and retained by the owner-user for the entire operational life of the tank until decommissioning and demolition:

• Design and Construction Dossier: Original fabrication drawings, design calculation sheets, foundation civil drawings, and material specifications.
• Material Test Reports (MTRs): Certified mill test reports documenting chemical composition, tensile strength, and Charpy V-notch toughness for all original and replacement shell, bottom, and annular plates.
• Alteration and Major Repair History: Complete engineering packages, stress re-evaluations, and Storage Tank Engineer sign-offs for all historical alterations, nozzle additions, and reconstructed courses.
• Hydrostatic Test Exemption Packages: Detailed fitness-for-service (FFS) assessments, brittle fracture evaluations, and NDE dossiers supporting hydrotest waivers under Section 12.2.1.6.
• Welding Quality Documentation: Certified Welding Procedure Specifications (WPS), Procedure Qualification Records (PQR), and Welder Performance Qualifications (WPQ) for all structural welding.

2. Progressive Inspection Records

Progressive inspection records document the ongoing physical condition of the tank over successive operating cycles. These records must be retained at least until the subsequent full internal inspection cycle is completed and integrated into historical corrosion trends:

• Routine monthly external inspection checklists.
• External ultrasonic shell thickness survey reports.
• Complete formal out-of-service internal inspection reports.
• Annual cathodic protection pipe-to-soil potential logs.
• Foundation settlement survey history.

Mandatory Transfer of Records Upon Facility Sale

Under API 653 Section 6.8, when a storage tank or terminal facility is sold or transferred to a new operating entity, all permanent and progressive records must be legally transferred to the new owner-user.

[!IMPORTANT] If an owner-user acquires a storage tank with missing or incomplete permanent records (e.g., missing material test reports or shell thickness baseline data), API 653 dictates that the missing parameters must be treated conservatively: joint efficiency must be downgraded to $E = 0.70$, material yield strength assumed as $30,000\text{ psi}$, and comprehensive physical metallurgical sampling or Charpy impact testing performed per Section 5 before re-rating the vessel.