Tank Inspection, Repair, Alteration, and Reconstruction

Our tank inspectors are certified to API 653 and possesses extensive experience in carrying out above ground tank inspection. The inspectors are well competent in tank construction codes, various NDT techniques, various damage mechanism, welding and corrosion of metals having qualification in ASNT, AWS, CSWIP and NACE.

API 653 : Tank Inspection, Repair, Alteration, and Reconstruction

Let’s get acquainted with the basic guide for Above Ground Storage Tank (AST) Inspection.

INTERNAL INSPECTION-SHELL PLATE

• Shell plate inspection for corrosion and deformation
• Shell plate circumferential and longitudinal welding joints inspection for corrosion and cracking
• Internal coating inspection (if any).

INTERNAL INSPECTION- BOTTOM PLATE

• Thickness measurement and remaining life calculation on bottom plates and annular plates
• Bottom plates and annular plates inspection for corrosion and deformation
• Bottom plates and annular plates welding joints inspection for corrosion and cracking specifically the annular plate joints with first shell course plate
• Sump inspection
• Internal coating inspection (if any)
• Inspection of sample plate, which must be cut to find any external corrosion
• Vacuum testing inspection and supervision

INTERNAL INSPECTION-FIX ROOF

• Roof plate inspection for corrosion and deformation
• Roof structure members inspection for corrosion and deformation
• Roof plates and structure members welding joints inspection for corrosion and cracking
• Internal coating inspection (if any)

INTERNAL INSPECTION-FLOATING ROOF

• Roof plate inspection for corrosion and deformation
• Roof structure members inspection for corrosion and deformation
• Roof plates and structure members welding joints inspection for corrosion and cracking
• Roof sealing system inspection
• Roof leg supports inspection
• Pontoon gasoil leak testing
• Internal coating inspection (if any)
• Roof drain system inspection

EXTERNAL INSPECTION-SHELL AND ROOF

• Thickness measurement and remaining life calculation
• Shell and roof plates inspection for corrosion and deformation
• Shell and roof plates circumferential and longitudinal welding joints inspection for corrosion and cracking
• Nozzles, man ways, flange welding joints inspection for corrosion and cracking
• External part of annular plates inspection, specifically welding joint with shell plates
• Side vents inspection
• Gasket seating surface inspection of nozzles and man ways flange joints
• Top angle, wind girder and stair way inspection for corrosion and deformation
• Roof sump inspection (floating roof only)
• Pontoon and pontoon structure welding joints inspection for corrosion and cracking (floating roof only)
• Weather shield rubber and pontoon doors rubber inspection (floating roof only)
• Pontoon air leak testing (internal floating roof only)
• Painting or insulation inspection

EXTERNAL INSPECTION-FOUNDATION

• Concrete foundation inspection for corrosion and cracking
• Earthling system inspection
• Asphalt inspection (around shell)
• Cathodic protection system inspection

TANK FLOOR MFL SCANS – INTERNAL TANK INSPECTION

• Application: On storage tank bottoms for all industries: upstream, mid-stream, petrochemical, refineries.
• Purpose: To identify soil and product side metal losses, pitting and general corrosion.
• Fast method for inspecting large areas; Minimal set-up time
• Reliable and economic qualitative tank floor assessments. High sensitivity: acceptable sensitivity can be obtained through up to 0.500” of combined steel and coating thickness
• Requires access to only one side of the material

MFL – MAGNETIC FLUX LEAKAGE

Magnetic Flux Leakage (MFL) or also known as Magnetic Flux Exclusion (MFE) is a magnetic method of nondestructive testing used to detect product side and soil side corrosion in above ground storage tanks.

Detected areas must then be further evaluated “proved up” utilizing Ultrasonic Thickness (UT) and/or Pit Gauging.

EILAB provides clients with API 653 tank bottom inspections using certified technicians and advanced inspection equipment. EILAB utilizes MFE Tank Floor Scanners (FloorMap VS2i) having following features.

• 3D Reporting suite with full version software
• Displays Digital Volume Loss Signals in real time
• Adjustable Threshold & Sensitivity
• Adjustable Display Brightness capable of viewing in sunlight
• Adjustable Gain for improving signal and reducing noise
• Scan speeds up to 0.5 m per second
• Perform through coating inspections, if non-magnetic, up to 6 mm coating thickness
• Perform inspections up to 20 mm thick plate
• 250 mm Scan Width, 15 m single scan length
• Battery powered for over 12 hours of continuous use

VACUUM BOX INSPECTION – EXTERNAL TANK INSPECTION

Vacuum box testing is a non-destructive examination used when trying to locate weld seam leaks. A vacuum box and a compressor create a high or low-pressure vacuum while a detergent solution is applied to the test area. The detergent bubbles, making leaks visible within the created pressure envelope.

Leak detection on objects on which a pressure differential can be created across the area can be examined. EILAB utilizes systems compliant with ASTM E515. All inspections are conducted within the parameters of ASME Section V Article 10, Appendix II or to client specifications.

• Application :On storage tank shells for all industries: upstream, mid-stream, petrochemical, refineries.
• Purpose :Bubble Leak Testing for Storage Tank Weld Seams
• Provides an immediate indication visual of the location of any leaks present
• Can detect small leaks within a given area
• Detect leaks from Lap welds, butt welds, and shell to annular welds
• Detect leaks on Tank bottoms
• Detect leaks from ERW seamed pipe in pipelines