Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
API DR 342-2002 Scan: Refractory Material Performance and Installation Criteria for Petroleum Refining Hearth Systems
Technical Requirements and Compliance Guidance for Hearth Department Refractory Linings in High-Temperature Hydrocarbon Service
1. Scope and Purpose of API DR 342-2002 Scan
API DR 342-2002 scan, issued by the American Petroleum Institute’s Hearth Department, provides a comprehensive technical framework for the selection, installation, and evaluation of refractory materials used in petroleum refining furnace hearths and lower wall sections. The document, originally released in 2002 and made available as a scanned reproduction, consolidates industry best practices and establishes minimum performance criteria for refractory castables, bricks, and insulating materials operating in direct contact with hydrocarbon combustion environments.
The standard applies to all fired heater hearths, including those in crude distillation units, catalytic reformers, and hydrogen reformers. It addresses material degradation mechanisms unique to hearth environments—such as alkali attack from fuel ash, thermal shock during start-up cycles, and mechanical abrasion from soot blowing systems. The scope extends to both monolithic linings and pre-fired shapes, covering new installations, repairs, and periodic condition assessments.
2. Technical Requirements
2.1 Material Classification and Properties
API DR 342-2002 scan classifies refractory materials into three service classes based on maximum operating temperature and chemical exposure:
- Class A (Severe Service) – For hearth zones above 1,100°C with potential for molten slag contact. Requires alumina content ≥ 60 % and apparent porosity ≤ 18 %.
- Class B (Moderate Service) – For intermediate zones between 900°C and 1,100°C with limited chemical attack. Alumina content between 45–60 % and porosity ≤ 22 %.
- Class C (Light Service) – For backup insulation and cold-face linings below 900°C. Cold crushing strength (CCS) ≥ 20 MPa.
The standard mandates that all materials undergo pre-installation qualification testing in accordance with the test methods listed in Table 1.
| Property | Test Method Reference | Class A Requirement | Class B Requirement |
|---|---|---|---|
| Cold Crushing Strength (MPa) | ASTM C133 | ≥ 50 | ≥ 35 |
| Permanent Linear Change (%) @ 1,250°C | ASTM C113 | –0.5 to +0.5 | –1.0 to +1.0 |
| Thermal Conductivity (W/m·K) @ 800°C | ASTM C201 | ≤ 1.5 | ≤ 1.8 |
| Abrasion Resistance (cc loss) | ASTM C704 | ≤ 10 | ≤ 15 |
| Alkali Resistance (strength retention after test) | API MPMS 5.6 (modified) | ≥ 85 % | ≥ 75 % |
2.2 Installation Criteria
Section 4 of the report details specific installation procedures to ensure lining integrity. Key requirements include:
- Anchoring systems: Alloy composition must match maximum hearth temperature; weld spacing ≤ 300 mm for Class A, ≤ 350 mm for other classes.
- Mixing and placement: Castable materials must be mixed for at least 5 minutes using paddle mixers; water content tolerance ±0.5 % of manufacturer’s recommendation.
- Curing and dry-out: The standard defines heating rate schedules based on lining thickness and moisture content. For hearth bottoms thicker than 300 mm, the temperature rise must not exceed 15°C per hour during the critical moisture removal stage (100–150°C).
Important: API DR 342-2002 scan warns that rapid heating of monolithic refractories above 150°C before complete moisture release can cause explosive spalling. The scannable appendix includes a dry-out curve reference chart for Class A materials that must be followed explicitly.
3. Implementation Highlights
3.1 Quality Control During Installation
The Hearth Department report emphasises the need for continuous quality surveillance during installation. Every batch of castable material must be sampled for consistency; at least one cube per cubic metre of installed volume must be cast and tested for density and CCS (cold crushing strength). The report permits the use of non-destructive ultrasonic testing to verify thickness uniformity of applied linings, with a minimum pulse velocity threshold of 2,500 m/s for Class A materials.
3.2 Inspection and Condition Assessment
API DR 342-2002 scan outlines a condition assessment protocol based on visual inspection, hammer sounding, and thermography. It defines four condition grades:
- Grade 1 – Minor fissures (< 2 mm), no exposed anchors. No action required.
- Grade 2 – Cracks 2–6 mm, limited spalling (depth ≤ 15 mm). Schedule repair within next turnaround.
- Grade 3 – Cracks > 6 mm, exposed anchors, delamination observed. Immediate repair required.
- Grade 4 – Hearth lining missing or collapsed. Furnace must be taken out of service and relined before restart.
Best Practice: For hearths operating with high-vanadium fuel oils, the standard recommends annual thermographic scanning (hence ‘scan’) to detect hot spots and internal delamination. This proactive approach has been shown to extend lining life by 30–50%.
4. Compliance Notes
4.1 Documentation Requirements
To demonstrate compliance with API DR 342-2002 scan, the responsible party must maintain a Hearth Refractory Dossier containing:
- Manufacturer’s certificates of analysis for each batch of refractory material.
- Pre-qualification test results including all properties listed in Table 1.
- Detailed installation logs recording ambient temperature, water addition, mixing time, and curing heat-up rates.
- Inspection reports with condition grading and photographs of documented areas.
All records must be retained for the full service life of the lining system.
4.2 Non-Conformance and Corrective Action
When a hearth lining fails the acceptance criteria of API DR 342-2002 scan, the standard mandates a root cause analysis (RCA) addressing material, design, installation, or operational factors. Corrective actions may include:
- Material replacement if batch testing reveals non-conforming CCS or porosity.
- Anchorage redesign if spalling is linked to excessive mechanical restraint.
- Modified dry-out schedules if moisture-related defects are identified.
Non-Compliance Risk: Failure to adhere to the dry-out curve specified in the scanned appendix can render the lining unserviceable and void any manufacturer warranty. Operators found using non-compliant materials or procedures may be subject to API audit flagging and insurance non-coverage for hearth failure events.
4.3 Periodic Re-Certification
API DR 342-2002 scan advises that hearth linings be re-certified every five years by a qualified refractory engineer. Re-certification includes a review of operating history, thermographic survey, and at least one core sample for density and strength verification. Any decline in material properties beyond 20 % of original values constitutes a trigger for relining evaluation.
Tip: When scheduling re-certification, coordinate with planned furnace turnarounds to minimise downtime. The scanned report provides an inspection checklist (Appendix C) that personnel can use during burner-management system shutdowns.
5. Frequently Asked Questions
Q: What does ‘scan’ refer to in the report title API DR 342-2002 scan?
A: ‘Scan’ originally designated the use of portable thermographic scanning equipment to detect subsurface defects in hearth refractories. The term was later retained in the standard’s title to emphasise the importance of non-destructive scanning techniques during condition assessments.
A: ‘Scan’ originally designated the use of portable thermographic scanning equipment to detect subsurface defects in hearth refractories. The term was later retained in the standard’s title to emphasise the importance of non-destructive scanning techniques during condition assessments.
Q: Is API DR 342-2002 scan still the current API document for hearth refractory evaluation?
A: As of 2025, API DR 342-2002 scan remains an active industry reference, though API periodically issues addenda as scanned pages (e.g., Scan A-2008, Scan B-2015). The 2002 base report has not been superseded; operators should verify they hold the latest scanned revisions.
A: As of 2025, API DR 342-2002 scan remains an active industry reference, though API periodically issues addenda as scanned pages (e.g., Scan A-2008, Scan B-2015). The 2002 base report has not been superseded; operators should verify they hold the latest scanned revisions.
Q: How does this report relate to API Standard 560?
A: API 560 covers fired heater general design, while API DR 342-2002 scan provides specific refractory material and installation requirements for hearth zones. They are complementary; contracts often reference both documents together.
A: API 560 covers fired heater general design, while API DR 342-2002 scan provides specific refractory material and installation requirements for hearth zones. They are complementary; contracts often reference both documents together.
Q: Are the test methods in Table 1 mandatory for all suppliers?
A: Yes. The standard mandates that all hearth refractory materials supplied to API-referenced projects must have documented test results from the listed ASTM methods. Suppliers may propose equivalent ISO methods only with prior approval from the purchaser’s refractory engineer.
A: Yes. The standard mandates that all hearth refractory materials supplied to API-referenced projects must have documented test results from the listed ASTM methods. Suppliers may propose equivalent ISO methods only with prior approval from the purchaser’s refractory engineer.
Article compiled from API DR 342-2002 scan (Hearth Department Report) – guidance applies to projects initiated after January 2026.