Heat Exchangers

Usually under the guidance of our clients, we offer general pressure vessel inspection services according to API 510. We can perform full external (in-service) or internal (out-of-service) inspections as required.

 

Advantages :

• Complete report attesting to observations according to API 510 requirements
• Certified and competent staff
• Proficiency in advanced testing to suggest optimal inspection techniques and properly interpret results

 

To note :

• An API 510 inspector cannot issue an internal or external pressure installation periodic inspection certificate. Only an inspector employed by a firm qualified in pressure installations according to the applicable legislation can produce such certificate.

The IRIS technique essentially consists of measurements of thicknesses from the inside of the tubes by immersion ultrasonic testing. A turbine activated by the water jet, also used for immersion, rotates a mirror at 45 degrees, which allows rapid thickness measurements to be taken around the entire circumference, and over the entire accessible length of the tubes.

 

Advantages :

• Precise thickness measurements
• Excellent detection of internal or external thickness losses

To consider :

• Requires water supply (difficult below freezing temperature)
• Requires a good cleaning of the tubes to have quality data
• Difficult, or impossible to cover the "U bends", depending on the diameters
• Possibility to record longitudinally encoded data for better longitudinal positioning, and for monitoring over time

RFT ("remote field testing") technique uses the phase and amplitude variations of the magnetic field to perform discontinuities detection. RFT is often used for its speed in order to cover a large number of tubes, followed by measurement validation using IRIS technique.

 

Advantages :

• Much faster than the IRIS technique
• No need for immersion (no need for water)

 

To consider :

• Applicable to ferromagnetic materials only
• Requires representative calibration tube
• Less precise thickness measurements than IRIS
• Possibility to record data according to the longitudinal position for accurate positionning of defects and the follow-up in time
• Possibility of using an automated pusher-puller to increase productivity

NFT ("near field testing") technique uses phase and amplitude variations of the magnetic field to achieve discontinuities detection. NFT is used for fin fan tubes rather than RFT because it is not affected by the outer fins of the tubes, and is often used to cover a large number of tubes, followed by measurement validations using IRIS.

 

Advantages :

• Much faster than the IRIS technique
• No need for immersion (no need for water)

To consider :

• Applicable to ferromagnetic materials only
• Ineffective for defects on the outer surface of tubes
• Requires representative calibration tube
• Less precise thickness measurements than IRIS
• Possibility to record data according to the longitudinal position for accurate positionning of defects and the follow-up in time

The eddy current inspection method is based on electromagnetic induction. The defects present in the tube have the effect of disturbing the flow of eddy currents and their induced magnetic fields. The instrument shows amplitude and phase variations of the impedance of the probe. This technique is generally used for non-ferromagnetic materials and / or for crack detection.

 

Advantages :

• Very fast
• Very good sensitivity to small indications, including cracks
• No need for immersion (no need for water)

To consider :

• Requires representative calibration tube
• Material penetration limitation for thicker tubes
• Possibility to record data according to the longitudinal position for accurate positionning of defects and the follow-up in time
• Possibility of using an automated pusher-puller to increase productivity

The ultrasonic phased-array technique allows multiple angles to be used simultaneously, creating a two-dimensional view in a pie shape. This greater coverage of the wall or weld section allows rapid detection of cracks on the opposite surface, as well as a good interpretation of the type of defect.

Advantages :

• Fast scans with excellent probability of detection
• Characterization and precise positioning of defects
• Volumetric inspection, not just on the surface
• As effective for inspecting "T" joints as butt joints
• Applicable on hot surfaces (variable maximum temperature)

To note :

• Requires application of couplant to inspection surfaces
• Sensitive to irregularities at the contact surface
• Technique sensitive to very small defects, on the other hand, a crack must be of a certain depth to be characterized as such (from 1 to 3 mm depending on the application)

Certifications:

• ASNT, SNT-TC-1A, Ultrasonic testing and PAUT, level 2 and 3
• CGSB, Ultrasonic Testing, level 2
• API, QUPA
• ASNT, Ultrasonic Testing, level 3

We generally use "phased-array" ultrasonic testing for the detection of loss of thickness in the walls, heads and nozzle necks of equipments.

This technique provides fast coverage and excellent interpretation of surface profiles.

Advantages :

• Precise thickness data
• Rapid coverage of large areas
• Excellent interpretation of the type of dammage
• Possible to inspect through a uniform and well-adhered paint
• Applicable on hot surfaces (variable maximum temperature)

To consider :

• Need to apply couplant to the contact surface
• It may be difficult or impossible to take measurements from a heavily corroded contact surface
• Measurements may become more difficult to take when the remaining thickness is less than 1 to 3mm (depending on the application)

Phased-array ultrasonic thickness measurement data can be recorded based on position to obtain detailed thickness mapping for the region of interest. Different scanners can be used, including a magnetic robot with a range of 60 feet, or a pipe elbow scanner. But more frequently we use a small encoder attached to the probe for versatility, being that obstacles are often present in the areas of interest (nozzle, walkways, ladders, insulation, etc.).

Advantages :

• Efficient and detailed thickness mapping
• Data available in Excel format for "fitness for service" calculations or monitoring of progress over time
• Very versatile technique
• During shutdowns, this technique applied from the inside allows excellent detection of CUI (corrosion under insulation)

To consider :

• Requires application of couplant or water to the contact surface
• Magnetic robot can be used to reach remote areas

Technician Certifications:

• ASNT, SNT-TC-1A, PAUT
• ASNT, UT level 3

We master 3D scanning technologies which allow us to obtain accurate profiles of loss of thickness or deformation. The use of self-adhesive targets on the inspected surface allows very precise scanning of the surface profile, even on site.

Applications:

• Characterization of areas of corrosion or deformation
• Extensive damage impact assessment using finite element analysis
• Monitoring of damage development over time

To note :

• The surface must be dry and not very reflective.
• The technique models any material on the surface, so also paint, deposits or corrosion. It is necessary to clean the surfaces of interest for more precision.
• The result obtained is the profile of the modeled surface, and not directly the wall thickness, it is necessary to supplement with ultrasonic testing to judge the remaining thicknesses.
• The technique requires some clearance (min 12 ") from the surface of interest.

Phased-array ultrasound provides excellent detection of defects through wall thicknesses, such as hydrogen blisters (HICs). It is possible to perform manual scans for detection. On the other hand, for a more precise follow-up over time of a given region, or for the mapping of an area with the presence of HIC, it is preferable to encode the data of the area in question using various types of scanners.

 

Advantages :

• Detailed mapping of indications
• Data saved for comparison over time

 

To Consider :

• Requires application of couplant or water to the contact surface
• Requires precise tracing of encoded areas, as well as fixed markers to be able to reproduce the inspection later

 

Technician Certifications:

• ASNT, SNT-TC-1A, PAUT
• ASNT, UT level 3

Magnetic particles non-destructive testing method is very efficient and simple to perform. It detects defects emerging at the surface in ferromagnetic materials. A magnetic yoke is generally used to create the magnetic field.

Different Techniques:

• Dry powder (yellow or red)
• Black particles on a white background ("black & white")
• Fluorescent particles (in dark environment)

Advantages :

• Fast and effective
• Excellent probability of detection
• Applicable on various geometries
• The dry powder technique is applicable at high temperature

To note :

• Applicable only to ferromagnetic materials
• Detection of surface defects, or very close to the surface, only
• Requires a clean surface (no grease)

Technician Certifications:

• ASNT, SNT-TC-1A, Magnetic Particles, Level 2
• CGSB, Magnetic Particles, Level 2

The non-destructive liquid penetrant testing method is simple to perform, but requires a few successive steps. This method makes it possible to detect cracks or other defects opened or connected to the surface, and is mostly used for non-ferromagnetic materials, such as aluminum or stainless steels.

 

Advantages :

• Simple execution
• Excellent probability of detection
• Applicable on a wide variety of geometries

 

To note :

• Requires a very clean, paint-free surface
• Inspected surface should be rather smooth, difficult to apply on porous surfaces
• More "messy" process

 

Certification of Inspectors:

• ASNT, SNT-TC-1A, PT Level 2
• CGSB, PT Level 2

Boroscopic cameras are generally used to validate the interpretation or the presence of defects, or to validate the quality of tube cleaning.

 

Advantages :

• Taking pictures of specific defects
• Very easy to perform
• Validation of the cleaning of the inside of the tubes

To consider :

• Tubes must be cleaned well enough to observe surface defects
• Limited or impossible detection of internal cracking