LoRUS

Hidden corrosion on difficult to reach places such as walls and bottoms of storage tanks causes serious problems in (petro) chemical plants. Early detection is often impossible or very expensive, as the object concerned will have to be taken out of service. The LoRUS (Long Range Ultrasonics) method was developed in order to be able to screen the annular plates, using a manipulator. This will allow users to detect on-stream hidden corrosion in time.
Key features of LoRUS
Performance
  • Scanning speed of 100' per day
  • Resolution 0.1 centimeter
  • Temperatures from 32° F to 122° F/ 0°C and 50 °C
  • Wall thickness at annular outside: ≥ 6,0 mm
  • Width annular outside: ≥ 5 cm
Cost savings
  • The storage tank doesn’t have to be taken out of service
  • Hidden corrosion can be detected onstream
Operation
The LoRUS equipment uses a manipulator to move the probes and record the position and scan direction. The ultrasonic signals are projected according to the probe directions and indications from the object under examination are color coded and presented in a 2D top view. All four probes are moved automatically across the examination surface by the manipulator.
 
Conditions
For a correct examination and evaluation of LoRUS (Long Range Ultrasonic) of the annular plates of a storage tank bottom it is necessary that the circumstances comply with certain conditions. These conditions are described and explained below:
 
1. Free space
To ensure free movement of the manipulator a free space is required, without obstacles (like nozzles, piping, cables, supports, insulation), with the following dimensions:
• Minimum 1 m high on the tank wall, measured from the annular plate
• Minimum 1 m between obstacles
Areas below obstacles can not be examined, just as 20 cm on each side of these obstacles.
 
2. Surface condition
For a good examination the external part of the annular must meet the following requirements:
• Minimum 50 mm wide (flat part beside the corner weld)
• Clean and flat, without coating, scaling, weld spatter, topside corrosion
• Actual wall thickness minimum 6 mm
• Bottom side corrosion of the external part can restrict the coverage of the LoRUS examination
• Maximum temperature 0° till 50°C
To remove the coating (sand)blasting is advised to get the best result. If necessary the surface can be cleaned with a (rotating) brush or fine sandpaper, but do not grind. The coating on the tank wall does not have to be removed, provided it is well bonded and flat.
 
3. General
- The tank wall must be carbon steel (for the magnetic wheels of the manipulator)
- Fresh water is used as couplant
- The equipment is not Explosion-proof
- To verify geometrical signals of internal attachments on the wall and annular, the client is requested to provide information about this
- Fluid level in the tank minimum 2 m during the examination
 
Benefits
The storage tank does not need to be offline or taken out of service. 
Hidden corrosion can be detected on stream saving time, money and resulting in overall efficiency.
 
Our solution
Applus+ RTD has developed the LoRUS method  in order to be able to screen the annular plates using a manipulator, allowing for detection of hidden corrosion while the asset is on-stream. The ultrasonic signals are projected according to the probe directions and indications from the object under examination are color coded and presented in a 2D top view. All four probes are moved automatically across the examination surface by the manipulator.
Spacer
Request a quote