172
Fundamentals of Corrosion
7. Inspection of the lining
8. Safety
9. Causes of failure
10. Operating instructions
6.1 Liquid Applied Linings
Liquid applied linings are coatings that can be applied by spraying or by
troweling. As mentioned previously, if a tank lining is going to provide the
corrosion protection desired, it is essential that the:
1. Vessel is properly designed
2. Correct coating is specified for the application
3. Vessel shell is properly prepared
4. Coating is properly applied and inspected
6.1.1 Design of the Vessel
All vessels to be lined should be of welded construction. Riveted tanks will
expand or contract, thus damaging the lining and causing leakage. Buttwelding is preferred but lap welding may be used, providing a fillet weld is
used and all sharp edges are ground smooth (see Figure 6.1). Butt welds need
not be ground flush but they must be ground to a smooth, rounded contour.
A good way to judge a weld is to run your finger over it. Sharp edges can be
detected easily. All weld spatter must be removed (see Figure 6.2).
Grind smooth
Weld
Inside of vessel
Inside of vessel
DO
DON’T
Gap
Gap
Round corners
Continuous fillet weld
FigurE 6.1
Butt welding preferred rather than lap welding or riveted construction.
Fundamentals of Corrosion
7. Inspection of the lining
8. Safety
9. Causes of failure
10. Operating instructions
6.1 Liquid Applied Linings
Liquid applied linings are coatings that can be applied by spraying or by
troweling. As mentioned previously, if a tank lining is going to provide the
corrosion protection desired, it is essential that the:
1. Vessel is properly designed
2. Correct coating is specified for the application
3. Vessel shell is properly prepared
4. Coating is properly applied and inspected
6.1.1 Design of the Vessel
All vessels to be lined should be of welded construction. Riveted tanks will
expand or contract, thus damaging the lining and causing leakage. Buttwelding is preferred but lap welding may be used, providing a fillet weld is
used and all sharp edges are ground smooth (see Figure 6.1). Butt welds need
not be ground flush but they must be ground to a smooth, rounded contour.
A good way to judge a weld is to run your finger over it. Sharp edges can be
detected easily. All weld spatter must be removed (see Figure 6.2).
Grind smooth
Weld
Inside of vessel
Inside of vessel
DO
DON’T
Gap
Gap
Round corners
Continuous fillet weld
FigurE 6.1
Butt welding preferred rather than lap welding or riveted construction.