Pressure vessel inspections

RITC (Pty) Ltd provides inspection and testing services to ensure that pressure vessels are fit for service and legally compliant to the Pressure Equipment Regulations.  All inspections and tests are carried out by suitably qualified and competent SAQCC/ SAIW certified inspection personnel.

In cases where vessels are not compliant with the Pressure Equipment Regulations, recommendations are provided to attain legal compliance and remain in service.

Types of inspection services offered:

Third party inspection and design verification on newly manufactured pressure vessels.

  • Pre shipment inspection including conformity assessments.
  • Pre commissioning inspection of newly installed pressure vessels.
  • Statutory inspection of in-service pressure vessels.
  • Re instatement to conformity of non-compliant pressure vessels.
  • Third party inspection on repairs to pressure vessels.
  • API 510 pressure vessel inspections.

Codes, standards, specifications and the Health and Safety regulations to which RITC are accredited to are referenced on our SANAS schedule of accreditation.

Steam generator (Boiler) inspections

RITC (Pty) Ltd provides inspection and testing services to ensure that steam generators are fit for service and are legally compliant and in accordance with the Pressure Equipment Regulations.  All inspections and tests are carried out by suitably qualified and competent SAQCC/ SAIW certified personnel. In cases where steam generators are not compliant with the Pressure Equipment Regulations, recommendations are provided to attain legal compliance for continued operation.

Types of inspection services offered:

Pre- commissioning inspection on newly installed steam generators.

  • Third party inspection and design verification on the manufacturing of steam generators.
  • Third party inspection on repairs of steam generators.
  • Re instatement of conformity of non-compliant steam generators.
  • In- service inspection of steam generators:
    • 3 yearly – Fire Tube steam generators
    • 3 yearly – water tube and electrode boilers
    • 12 monthly – Fire Tube Steam generators
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Third party AIA inspection

Types of inspection services offered:

  • New fabrication of pressure equipment (Typical codes of manufacture ASME VIII, PD 5500, ASME B31.1, B31.3, B31.4, B31.5, B31.8 & API 650)
  • Fabrication of Structural steel structures (AWS D1.1)
  • Fabrication of Bulk Vertical Storage tanks (API 650 & 653)
  • Fabrication of Pipelines (ASME BS 31.1,3,4 & 8, API 1104)
  • Repairs and Alterations to above (API 510, API 570, API 653, NBIC & ASME PCC-2)

Weld Procedure Qualifications and Weld Qualifications:

Through our qualified and experienced welding inspectors we can assist in the preparation and qualification of manufacturing weld procedures to various national and international codes and specifications.

Weld procedure qualifications:

  • Witness welding of test piece.
  • Mechanical testing and radiographic testing of the test piece as per code requirements.
  • Drafting and approving weld procedure qualifications according to various codes such as ASME VIII, AWS D1.1, EN 14025 and 9606
  • Drafting of qualified and prequalified procedures.

Welder qualifications:

  • Witness welding of test piece
  • Mechanical testing and/or radiography of test piece as per code requirements.
  • Drafting of welder qualification certificates according to codes such as ASME VIII, AWS D1.1, EN 14025 and 9606

API 653 Storage Tank Inspections

In service and out of service inspections are carried out in accordance with API 653 recommendations. Visual inspections are carried out by our API inspectors who are qualified and certified to API 653 requirements. These inspections are supplemented by specialized high-tech testing techniques to enable our clients to be provided with a detailed integrity and condition report including estimated remaining life and retirement dates for the tank.

  • The Floormap3Di-R is the fastest tank bottom inspection system developed by Silverwing, with scanning speeds of up to 1 m/s.
  • MFL Floormapping technique provides an image of both topside and underside corrosion of the tank floor plates with recorded volumetric losses in thickness.
  • This information is used to calculate corrosion rates and estimated remaining tank life.
  • This inspection technique is used on tank shells to determine remaining thicknesses and to also identify any areas of corrosion.
  • It can be used externally while the tank is in service and has an automated crawler mechanism thereby eliminating the need for scaffolding or manual thickness gauging.
  • The RMS can give 100% wall thickness reading coverage in a band up to 600mm wide, significantly increasing Probability of Detection (PoD) of random defects and corrosion.
  • The Scorpion B-scan dry-coupled, remote-access ultrasonic crawler is also used on tank shells for determining general wall thickness and metal loss.
  • This technique is similar to the RMS with a much narrower scanning band of only 10mm.
  • Generally used for nominal wall thickness assessments and not for corrosion and defect location.
  • Bubble leak (or vacuum box) testing is used to assess weld condition and integrity of floor plate and floor to shell welds.
  • A vacuum is created through a custom designed box and a soapy water liquid is poured over the welds. Any pinholes, cracks or through wall weld defects will be identified by the presence of air bubbles.
  • This is a non-destructive testing(NDT) process for detecting surface and shallow subsurface defects in welds.
  • Generally used for testing tank shell penetrations, nozzles, compensation pads and floor plate welds. 
  • Calibration and strapping of storage tanks can be done to determine exact containment volumes.
  • Our technicians are all highly skilled and use Electro Optical Distance Ranging (EODR) laser scanning and 3D laser scanning to enable accurate excel strapping tables to be produced.
  • Tank geometric surveys can be carried out as part of the API 653 inspection assessment. This is carried out using laser survey and conventional measurement techniques.
  • These surveys include individual measurements for Tank Roundness/Ovality, Plumbness/Verticality, Shell Settlement and Bottom Profile.

API 570 Piping Inspection and Certification

  • Our API 570 Inspectors have inspected and certified pipelines ranging from large diameter lines used in oil and gas production through to smaller diameter pipelines used in Petrochemical plants, refineries and depots.
  • The inspection code covers in-service inspection, rating repair, and alteration of metallic and fiberglass-reinforced plastic (FRP) piping systems and their respective pressure relieving devices.

NON-DESTRUCTIVE TESTING

Non-destructive Examination (NDE) is defined as those inspection methods, which allow materials to be examined without changing or destroying their usefulness. NDE methods are employed to ensure that a WELD meets design specifications and does not contain defects. An NDE method is chosen that has the capability and adequate sensitivity to detect discontinuities in the WELD JOINTS requiring examination for accept/reject evaluation. Discontinuities in welds that are detectable when using NDE methods are Porosity, Incomplete fusion, Incomplete joint penetration, Undercut, Underfill, Lamination, Cracks, Root Concavity, Slag Inclusion Etc. 

Below are the NDE methods that RITC (Pty) Ltd offer:

Ultrasonic Testing:

Ultrasonic Examination (UT) can detect surface and subsurface discontinuities. A beam of sound in the ultrasonic frequency range (>20,000 cycles per second) travels a straight line through the metal and reflects from an interface. For weld inspection this high frequency sound beam is introduced into the weld and heat affected zone on a predictable path, which, upon reflection back from an interruption in material continuity, produces a wave that is electronically amplified to produce images. These images are displayed such that they can give both the size and positional information of the discontinuity.                       

Straight beam techniques are used for thickness evaluation or to check for laminations.

Shear wave or Angle beam techniques are employed for identification of discontinuities in welds. The sound beam enters the area of the weld at an angle. If the sound reflects from a discontinuity, a portion of the sound beam returns to the receiver where it is displayed on the ultrasonic instrument. From this display, information such as the size, location and type of discontinuity can be determined.

discontinuities, revealing a visual indication of the flow.

Has been recognized as one the best inspection techniques. It is efficiently used for finding fatigue cracking, SCC, or step wide cracking. It is a proven method for sizing indications and regular monitoring.

Ultrasonic wall thickness meters are used for wall thickness measurements. This is done to check the thickness of pressure vessels, storage tanks etc. By taking wall thickness measurements, it can tell you if the vessel has corrosion and you can work out the life span left on the vessel. According to regulations and codes certain vessels material need to be a certain thickness and it is thus a requirement to have this test done every three years.

UTM assessments are mandatory every five years for all Bureau Veritas classed vessels. This survey can detect even marginal steel corrosion, assessing the level of wear-and-tear on a ship and noting areas in need of repair.

Surface Flaw Detection:

Magnetic Particle Examination is effective in locating surface or near surface discontinuities of ferromagnetic materials. It is most used to evaluate weld joint surfaces of completed welds, intermediate checks of weld layers and back-gouged surfaces of welds. Typical types of discontinuities that can be detected include cracks, laminations, laps, and seams.

In this process, the weld (and heat-affected zone) is locally magnetized, creating a magnetic field in the material. Ferromagnetic particles are then applied to the magnetized surface and are attracted to any breaks in the magnetic field caused by discontinuities.

Liquid Penetrant Examination (PT) can detect surface-connecting discontinuities in ferrous and nonferrous alloys. PT can be used to examine the weld joint surfaces, intermediate checks of weld passes, and completes welds. PT is commonly employed on Austenitic Stainless steels and nonferrous metals where magnetic particle examination is not possible.

The test surface is cleaned and coated with a penetrating liquid that seeks surface-connected discontinuities. After the excess surface liquid penetrant is removed, a solvent-based powder suspension (Developer) is applied by spraying. The liquid in any discontinuity bleeds out to stain the powder coating. An indication of depth is possible if the technician observes and compares the indication bleed out to the opening size visible at the surface. The greater the bleed out to surface ratio, the greater the volume of the discontinuity.

Radiographic Testing: (RT)

Radiographic Examination (RT) is a volumetric method capable of examining the entire specimen rather than just the surface. It is used to examine completed welds for surface and subsurface discontinuities. The method uses the change of absorption of radiation by solid metal in areas of a discontinuity. The radiation transmitted reacts with the x-ray film and a latent image is captured on the film. When the film is processed (developed) a permanent image (radiograph) of the weld is created.

Some methods use electronics to create a digital image of the weld and no X-ray film is required.

Radiographic indications display a different density as contrasted with the normal background image of the weld. The NDT examiner performs the film interpretation, evaluation and reporting.

RT can be performed with a Gamma ray source or an X-ray unit.

Different radiography methods:

  • Conventional Gamma Radiography (Iridium 192/Selenium)
  • Heavy Wall Gamma Radiography (Cobalt)
  • Conventional Xray Radiography
  • Digital and CR Radiography
  • Safe-rad, close proximity Radiography

Safe-rad, close proximity Radiography

To perform Safe-Rad Radiography the barriers & sign posting can be set at 1 meter away from the radioactive source. Radiography can be carried out while other personnel are working in the same area. 

CONVENTIONAL GAMMA PROFILE RADIOGRAPHIC EXAMINATION TECHNIQUE

Gamma-Radiographic techniques provide accurate pipe wall measurements and permit inspection of the internals of some equipment. The primary function of this method is to detect metal loss. Pitting and other non-uniform corrosion can also be identified on the radiograph.

The pipe insulation can remain intact while doing Profile Radiography on the pipe line and large medical size film are normally used to capture as much detail as possible.

Advanced NDT:

Ultrasonic examination. It is probably the most versatile of the inspection techniques and used routinely as an inspection tool. In angle beam mode, ultrasonic examination can detect crack like defects down to less than 1 mm in size and can be used to size cracks down to less than 3 mm.

A physical evaluation or test of a material to confirm that the material which has been or will be placed into service is consistent with the selected or specified alloy material designated by the owner/user. These evaluations or tests provide information that is sufficient to verify the nominal alloy composition.

We use the Portable X-ray Fluorescence PMI test method. The principle of operation is that an X-ray source is used to generate a beam of low energy radiation to excite the material under analysis. The material under analysis then emits a characteristic radiation spectrum which can be analysed to determine which elements are present and in what quantity.

Automated spark testing has been developed to remove the reliance upon operator skill and experience, thereby increasing reliability. The system relies upon spectroscopy, spectrometry, and other methods to “observe” the spark pattern. It has been found that this system can determine the difference between two materials that give off sparks that are indistinguishable to the human eye. Spark testing involves the use of a field portable electronic instrument specifically designed to analyse metals and measure and quantify the chemical content. The instrument gives elemental content of metallic and non-metallic compounds which make up the material under analysis and will give the percentage content of the elements present

NDT VIA ROPE ACCESS

Rope access is an advanced access method that is used as an effective alternative to conventional scaffolding or cradle systems. Personnel are highly skilled in rope access techniques and related activities with accreditation conforming to the relevant codes of practice. The teams involved on a job are normally IRATA certified Level 1, Level 2 and Level 3 technicians. 

NDT and Inspection methods that can be carried out using Rope Access are the following:

  • Magnetic Particle Examination. (MT)
  • Liquid Penetrant Examination (PT)
  • Ultrasonic Examination. (UT)
  • Thickness Measurements. (UTM)
  • Radiographic Examination. (RT)
  • Positive Material Identification testing. (PMI)
  • Visual Inspection. (VT)