What are the pros of non-intrusive pressure equipment inspections?

By Krystal Nanan | Published: July 26, 2019 | Last updated: January 31, 2022

It is essential to perform regular inspections on pressure equipment to ensure that their mechanical and structural integrity meet safety and performance standards. Traditionally, internal visual inspections have been used to assess the condition of pressure vessels. However, these methods are typically associated with high costs and inconvenience to plant operations. (Corrosion of these vessels is discussed in detail in the article Introduction to Managing Internal Corrosion in Process Vessels.)

To overcome these inadequacies, non-intrusive inspections (NII) are frequently employed in many industrial facilities. Non-intrusive inspections consist of a range of techniques that allow operators to safely and effectively inspect vessels from their exterior. Some of the key benefits of non-intrusive inspections include:

  • Eliminate hazards associated with the manual entry into vessels – Since non-intrusive inspections are carried out on the exterior of the pressure equipment, there is no need for personnel to manually enter the vessel. This, in turn:
    • Eliminates the need to conform to confined space requirements and other safety protocols
    • Minimizes disturbance to the interior of the vessel, which can cause equipment damage or deterioration
  • Reduce the manpower and resources required for vessel inspection – In addition to inspectors, traditional internal investigations require the involvement of rescue, planning and plant operation personnel. In contrast, non-intrusive inspections only require an inspector (or inspectors) to operate the inspection equipment.
  • Eliminate the need to clean the internal surface of the vessel – Before internal visual inspections can be performed the inside of the tank or vessel must be prepared using a variety of cleaning methods. Steaming, cleaning solvents, grit blasting, wire brushing and pressure washing are just some of the cleaning methods that ultimately add to the total cost of visual inspections. Because non-intrusive inspections use imagery techniques from the vessel’s exterior, cleaning operations are not required.
  • No production losses associated with pressure vessel shutdown – Shutdowns are one of the most significant contributors to the costs associated with internal visual inspections. Because internal investigations require inspectors to enter the vessel, the equipment must temporarily cease operation. This lack of service, known as a shutdown, can result in significant revenue loss depending on the industry. With non-intrusive techniques, inspections can be performed while the equipment remains in operation.
  • Decreased inspection and turnaround times – Because non-intrusive methods require a smaller workforce and fewer secondary operations, the time to complete the inspection is significantly reduced.

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Written by Krystal Nanan | Civil Engineer

Krystal Nanan
Krystal is a civil engineer and project manager with an MSc in Construction Engineering and Management. Her experience includes the project management of major infrastructure projects, construction supervision, and the design of various infrastructure elements including roadway, pavement, traffic safety elements and drainage. Krystal is also a published author with the Transportation Research Board in Washington, D.C.

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