New and updated petrochemical complexes have become the mainstay of sustainable development in the oil, gas, and petrochemical industry. These chemicals manufacture plastics, fibres, cellophane, synthetic rubber, solvents, and various other chemicals. Keeping this in mind, petrochemical complexes are being constructed as greenfield projects with heavy investments from oil and gas companies.
These facilities must comply with ASME standards for pressure vessels to ensure the safe operation of the plant at all times. To continue confidently building new and updated petrochemical complexes that meet regulatory standards and demand, engineers invested in these projects require non-destructive testing (NDT) services to ensure the safety of all equipment throughout their life cycle.
This article explores A Basic Guide to NDT Services for Petrochemical Complexes & why these services are necessary, how they help reduce maintenance costs over time, and which ones you should leverage based on your specific needs.
What is Nondestructive Testing?
The most common types of NDT are Visual inspection, Ultrasonic Inspection & Radiographic Inspection, which are used to determine the homogeneity of materials and structures. The defects may be in the form of cracks, corrosion or other damage. In order to find these defects, NDT technicians will use specialized equipment to generate and collect data. After analysis of the collected data, they will determine if there is any defect in the structure or material.
The two most common types of NDT are visual inspection and radiographic inspection. Visual inspection is when a technician looks at an object with the naked eye. They may also use tools, such as a magnifying glass, a lens, or a microscope. Radiographic inspection is when technicians use X-rays, gamma rays, or other similar technologies to view the internal condition of the object.
Why Do You Need Non destructive Testing for Petrochemical Complexes?
Petrochemical complexes are large-scale industrial facilities that produce a large variety of chemicals, plastics, and synthetic materials from oil and natural gas. These facilities are very costly to build and operate. A critical factor in the operation of these facilities is determining the integrity of critical equipment like pipelines, pressure vessels, and boilers.
This equipment must be inspected for defects through non-destructive testing (NDT) methods. If any defects are found during NDT inspections, a repair can be made before the plant becomes operational. By implementing NDT methods to detect flaws, you can ensure that the equipment is safe to operate and will not contribute to a catastrophic industrial accident.
Petrochemical complexes are often located in remote locations and far from major cities.
Why Are NDT Services Important for Petrochemical Complexes?
NDT services are critical to the safety and maintenance of facilities in the petrochemical industry. From crucial safety equipment like pressure vessels to items like the structural integrity of piping systems, all components of the facility must be in good shape. Beyond the safety aspect, NDT services have a significant impact on long-term maintenance costs. If a critical part of the facility needs to be replaced, it can be very expensive.
However, if a defect is found and fixed in advance, then the replacement cost is dramatically reduced. As a result, petrochemical companies will see significant cost savings over the long term by using NDT services frequently.
Types of NDT for Petrochemical Complexes
NDT technicians may use several methods to inspect critical equipment in a petrochemical complex. The following is a list of standard NDT methods in order of increasing cost. Material Thickness Measurement and Geometric Dimensioning & Tolerance (GD&T) Compliance.
When a vendor delivers piping components to a petrochemical complex, they must follow the ASME B31.3 code. The code includes a requirement for the minimum wall thickness of each pipe. As the petrochemical complex is constructed, the piping will be cut and welded together to form a network of pipes.
This results in the minimum wall thickness being reduced since the weld is not as thick as the minimum wall thickness of the pipe wall. To ensure that the welded piping complies with the ASME B31.3 code, the engineers will use a GD&T tolerance table to select the minimum wall thickness of the welding electrode. The welding electrode will then be tested with a wall thickness gauge to ensure that it complies with the minimum wall thickness specified by the table.
If the welding electrode fails the wall thickness gauge test, then it does not comply with the code. Therefore, the piping will not meet the requirements of the ASME B31.3 code. This is critical because the risk of the piping failing increases if the welded piping does not meet the requirements of the code. The engineers can use NDT methods to detect the non-compliance of the welding electrode before they weld the piping together.
Ultrasonic Testing (UT)
There are several NDT methods that can detect cracks in critical components like large pressure vessels, large diameter piping, etc. One of the most common methods is ultrasonic inspection. This method uses a device that generates a high-frequency sound vibration between 18-200 kHz.
The sound waves are then used to detect defects such as cracks in the material. If a crack is present, the sound waves will travel through the crack and reflect back. The device that generates the sound waves will then detect the reflection and produce an alarm.
This alarm is an indication that there is a crack in the material. The ultrasonic inspection method can be used to inspect the following materials: – Carbon Steel – Stainless Steel – Cast Iron – Alloy steel.
Magnetic Particle (MP) Inspection
MR uses a powerful magnetic field to detect cracks in materials. The magnetic field can penetrate through the material and detect any defects. The defects can be cracks, voids, inclusions, etc. The MR equipment generates a powerful magnetic field that penetrates the material.
It will measure the energy loss of the magnetic field as it travels through the material. If there are defects in the material, the magnetic field will reflect the defects. This will cause energy loss and a reduction in signal strength. MR is used to inspect the following materials: – Cast Iron – Steel – Stainless Steel – Materials with ferromagnetic properties.
X-ray Diffraction (XRD) Inspection
The XRD method can detect the presence of voids and cracks in materials. An XRD machine will shoot a beam of X-rays towards the object. Some of the X-rays will be reflected back. The engineers will then collect this information and use it to determine the material’s structure.
If there is a void in the material, the void will block some of the X-rays. The XRD machine will then detect the reduced amount of X-rays that are reflected back. This is an indication that there is a void or crack in the material. XRD is used to inspect the following materials: – Carbon steel – Stainless steel – Cast iron.
The NDT services are crucial for petrochemical plants because these plants are complex industrial facilities and crucial industrial equipment such as pressure vessels, pipelines, boilers and reactors need to be inspected. When any defects are detected, the equipment can be repaired before installation.
Ixar Group is honoured to have been one of the “Top 10 Non-destructive Testing Consulting/Service Companies in India” for more than a decade.
Oct 26, 2023