Routine inspections are part of most industries, whether you’re in engineering, construction, healthcare, or just about any other profession. So when it comes down to inspections, it’s important to know what to look for and how to fix any potential problems that exist or may occur in the future. 

Pressure vessels maintain different criteria than typical storage tanks. Holding liquids, vapors, and gasses that require a pressure different than the ambient or air pressure, pressure vessels pose significant risks if not inspected and maintained properly. 

Being prepared for regular inspections of your company’s pressure vessels, such as the API 510 Pressure Vessel Inspection, is important in keeping your building, employees, and the general public safe. 

But what does the API 510 Pressure Vessel Inspection entail? Let’s take a look. 

API 510 Pressure Vessel Inspection 

A code written by the American Petroleum Institute, the API 510 Pressure Vessel Inspection not only covers the standards the vessel should meet but also logs any repairs that may be needed. 

The API 510 inspection evaluates pressure vessels both internally and externally for operational stability, material quality, storage capability, safety, measurements, and more. Over the years, technology and changes in general inspection practices have changed how the API 510 code and methods are used.

When a certified inspector completes a pressure vessel inspection, the inspector does more than just visually survey the vessel inside and out. 

These inspections use non-invasive and non-destructive testing methods to ensure that compliance is intact for all new and existing pressure vessels. 

Consider what could happen without these regular inspections. What if a unit malfunctions or is incorrectly manufactured? What if something is being overlooked with routine maintenance? Without routine inspections like the API 510 Pressure Vessel Inspection, serious failures and emergencies could occur.

Equipment Inspected

A complete API 510 Pressure Vessel Inspection covers more than just the shell of the vessel inside and out. All moving parts and operational equipment for the pressure vessel must be checked for standards and safety compliance. 

The following are inspected with the API 510 Pressure Vessel Inspection:

  • Drums
  • Towers
  • Shell and tube heat exchangers 
  • Air-cooled exchangers
  • Bullet tanks
  • Sphere tanks
  • Horton sphere tanks
  • Flare stack
  • Filters
  • Knock-out pots 
  • Boilers

Tests Covered in the API 510

A certified API inspection covers more than simple interior and exterior visual inspection of a pressure vessel/tank. 

Details of the API 510 inspection reports and code cover several areas including but not limited to:

  • Ultrasonic flaw detection
  • Magnetic particle and Dye penetrant testing 
  • Positive material identification
  • Corrosion under insulation inspection 
  • Leak testing 
  • Lead detection measures 
  • Fitness for service evaluations 
  • Risk-based inspections 
  • Repair and alteration inspection
  • Vendor surveillance 
  • Shop and warehouse audits
  • Inspection work plan development and execution
  • Adequate company training measures 

While there are different pressure vessels designed for holding different liquids, vapors, and gasses, most API 510 Pressure Vessel Inspections detail the same regulations according to API code. However, based on the pressure vessel you use, your pressure vessel inspection expert will define testing methods that are most suited to your facility and equipment. 

Types of API 510 Pressure Vessel Inspections

There are two different types of API 510 Pressure Vessel Inspections. 

Off-Stream Inspections

Off-stream inspections are directed towards vessels that have been taken out of service and are not presently operating. These inspections are, by API code, required every 10 years. To complete an off-stream inspection, the vessel needs to be opened and cleaned for entry. There are several inspection points covered in an off-stream inspection. 

Internal Inspections

Internal inspections are performed by an API 510 certified inspector and use a specific checklist to help ensure all areas of the vessel are inspected for proper function and mechanical integrity. This includes reviewing the vessels operating and inspection history to ensure that operating pressures and temperatures are occurring with the structural limits.

Components inspected during an internal and external inspection include the foundation, shell, heads, nozzles, ancillary equipment, and pressure relief valves. These components are inspected visually; however, if imperfections or abnormalities are detected or anticipated, further inspection utilizing non-destructive testing may be necessary. 

Ultrasonic Thickness Testing Inspections 

In contrast with the internal and external inspections, Ultrasonic Thickness Testing Inspections, or UTT, are performed by an ASNT Level II Certified UTT Inspector. This inspection focuses on ultrasonic monitoring of material thickness for pressure vessels holding gasses and vapors. Although thickness measurements are not required to be taken during an external inspection, thickness measurements share the same inspection interval as Internal inspections. Therefore, at a minimum, thickness measurements are taken during internal inspection, but are often taken at both external and internal inspections. 

This data is used to determine the corrosion rates and remaining life of the vessel. Measurements are taken at the following location: Shell course, internal and external heads, and nozzles are inspected using UT.. 

On-Stream Inspections 

External inspections are considered on-stream inspections because the vessel is not taken out of service. External inspections are to be performed at intervals: the lesser of 5 years or at the time of the internal inspection.

How Are Inspectors Certified? 

The API certification requirements to become an inspector are very similar to what you would see in other industries in terms of taking a course and passing an exam. 

The minimum requirement for taking the API examination is a two-year degree in engineering or technology paired with a minimum two years of skills and experience in design, repair, construction, operation, or inspection of pressure tanks. This includes one year of fully supervised inspection activities.

At that point, you are eligible to sit for the API exam. Passing the API exam requires a minimum 70 percent correct answers and will lead to your API ICEP (American Petroleum Institute Inspector Certification Endorsement Program) endorsement for that particular program. Each API document/area has its own ICEP. 

The more an inspector knows and understands about each service area, the better the inspection planning and execution will be. 

Request an API 510 Pressure Vessel Inspection with NDT Tanknicians 

We are only as good as the service we provide, and we go the extra mile to ensure all of our personnel are trained to industry standards. 

At NDT Tanknicians, we embrace the tough challenge set in place to be certified by entities such as the Environmental Protection Agency (EPA,) American Petroleum Institute (API,) Steel Tank Institute (STI,) American Society for Nondestructive Testing (ASNT,) and the National Association of Corrosion Engineers (NACE,) to name a few. 

We’re capable of providing top-to-bottom coverage for all of your Storage Tank requirements; servicing a broad spectrum of clientele, both small and large. Our ability to streamline an entire project gives us an edge over the competition by providing our clients with the peace of mind and convenience of trusting one service provider to become familiar with all of their current and future needs, rather than half a dozen. This keeps costs to a minimum, quality control consistent and communication among crews seamless. 

Request a quote today.