A Comprehensive Guide to Recognized And Generally Accepted Good Engineering Practices (RAGAGEP)

Introduction:

Recognized And Generally Accepted Good Engineering Practices (RAGAGEP) are derived from a combination of engineering knowledge, industry experience, standards, codes, and technical reports. This article delves into the application of RAGAGEP in storage tanks, their design, and inspection requirements.

What is RAGAGEP?

RAGAGEP involves the application of engineering, operating, or maintenance activities based on evaluated and analyzed internal and external standards, codes, and recommended practices. These practices can be derived from various sources, tailored to individual facility processes, materials, services, and engineering considerations.

Storage Tanks vs. Pressure Vessels:

Understanding the difference between storage tanks and pressure vessels is essential:

- Storage Tanks: Typically used for storing liquids at atmospheric pressure.

- Pressure Vessels: Designed to hold gases or liquids at a pressure substantially different from the ambient pressure.

Types of Storage Tanks:

1. Atmospheric Storage Tanks (AST): Designed to operate at pressures ≤ 2.5 psig.

2. Low-Pressure Tanks (LPTank): Operate at higher pressures, but not exceeding 15 psig.

Tank Design Codes:

1. API 650: For welded steel tanks for oil storage, covering materials, design, fabrication, erection, and initial acceptance tests for tanks operating up to 2.5 psig.

2. API 620: For large, welded, low-pressure storage tanks, covering materials, design, fabrication, erection, and initial acceptance tests for tanks operating up to 15 psig.

Floating Roof Tanks:

These tanks minimize vapor space by using a roof that floats on the surface of the stored liquid, thus reducing evaporation losses.

Other Relevant RAGAGEPs:

1. API RP 651: Cathodic protection of ASTs.

2. API RP 652: Lining of AST bottoms.

3. API 2000: Venting atmospheric and low-pressure storage tanks.

4. API RP 2003: Protection against ignitions from static, lightning, and stray currents.

5. API RP 2026: Safe access and egress involving floating roofs in petroleum services.

6. API 2350: Overfill protection for storage tanks in petroleum facilities.

Tank Inspection Code:

1. API 653: Governs the inspection, repair, alteration, and reconstruction of tanks designed to API 650. Key inspection activities include:

- Routine in-service inspections (monthly).

- External visual inspections (every 5 years or 1/4 of the remaining life).

- External thickness measurements (every 5 to 15 years, depending on corrosion rate knowledge).

- Internal visual/floor scan inspections (initially every 10 to 20 years, subsequently every 20 years).

Other Inspection Standards:

1. API RP 575: Inspection of atmospheric and low-pressure storage tanks.

2. API 579/ASME FFS-1: Fitness for service.

3. API RP 576: Inspection of pressure-relieving devices.

4. API RP 580: Risk-based inspection.

Conclusion:

Understanding and applying RAGAGEP ensures the safety, reliability, and efficiency of engineering operation. Regular inspections and adherence to relevant standards are crucial.

For more detailed discussions and resources, join our WhatsApp group. Additionally, get our comprehensive e-book for RM29, which includes RAGAGEP for tanks, pressure vessels, heat exchangers, and piping, to deepen your understanding and enhance your engineering practices.