adjacent areas mustb ed iscontinued during application and “no smoking”
must be the rule during application.
Ap ower airs upply and ventilation must be provided during the
application of the lining. The vapor concentration inside of the vessel
should be checkedonaregular basis to ensure that the maximum allowable
vapor concentration is not reached. For mostsolvents, avapor concentration
of between2%and 12% in the air is sufficienttocause an explosion. As long
as the vapor concentration is kept below the lower level,n oe xplosion will
take place. All electrical equipmentm ust be grounded.
Because flammables olvents areb eing exhaustedf romt he tank,
precautions must be taken on the exterioro ft he tank. These flammable
vapors will travel ac onsiderabled istance along the ground. No flames,
sparks,oru ngrounded equipment can be nearby.
Those applying the linings hould wear fresh airline respirators and
protective cream on exposed parts of the body.W ater should be available for
flushing accidental spills on the skin. Never allow one workeri nt he tank
alone.
OSHA issuesaf orm called the Material Data Sheet. The manufacturers
supplythis form by listing all toxicants or hazardous materials and provide a
list of the solventsused.Also included are the threshold limit values (TLVs)
for each substance. Explosive hazards, flash points,a nd temperature limits
are established for safe applicationo fe ach lining material. These Material
SafetyD ata Sheets should be kept on file in the job superintendents office
and at the first aid station.
4.9C auses of Lining Failure
Most liningf ailures are the result of the misuse of the tank lining, which
results in blistering, cracking, hardening or softening, peeling, staining,
burning, and undercutting. Afrequent causeoffailure is overheating during
operation. When aheavilypigmented surfaceorthick film begins to shrink,
stresses are formed on the surfacethat result in cracks. These cracks do not
always expose the substrate and may not penetrate. Under these conditions,
the best practice is to remove thesea reas and recoat according to standard
repair procedures.
Aging or poor resistance to the corrosive can result in hardening or
softening. As the coating ages, particularly epoxy and phenolic amines,
it becomesb rittle and may chip from the surface. Peeling can result from
improperly cured surfaces, poor surfacepreparation, or awet or dry surface.
Staining results when there is areaction of the corrosive on the surfaceofthe
lining or slight staining from impurities in the corrosive. The true cause must
be determined by scraping or detergent washing the lining.I ft he stain is
removed and softening of the film is not apparent, failure has not occurred.
Liquid-Applied Linings
83
CAT8247—CHAPTER 4—17/10/2006—14:33—SRIDHAR—XML MODEL B–pp. 69–174
must be the rule during application.
Ap ower airs upply and ventilation must be provided during the
application of the lining. The vapor concentration inside of the vessel
should be checkedonaregular basis to ensure that the maximum allowable
vapor concentration is not reached. For mostsolvents, avapor concentration
of between2%and 12% in the air is sufficienttocause an explosion. As long
as the vapor concentration is kept below the lower level,n oe xplosion will
take place. All electrical equipmentm ust be grounded.
Because flammables olvents areb eing exhaustedf romt he tank,
precautions must be taken on the exterioro ft he tank. These flammable
vapors will travel ac onsiderabled istance along the ground. No flames,
sparks,oru ngrounded equipment can be nearby.
Those applying the linings hould wear fresh airline respirators and
protective cream on exposed parts of the body.W ater should be available for
flushing accidental spills on the skin. Never allow one workeri nt he tank
alone.
OSHA issuesaf orm called the Material Data Sheet. The manufacturers
supplythis form by listing all toxicants or hazardous materials and provide a
list of the solventsused.Also included are the threshold limit values (TLVs)
for each substance. Explosive hazards, flash points,a nd temperature limits
are established for safe applicationo fe ach lining material. These Material
SafetyD ata Sheets should be kept on file in the job superintendents office
and at the first aid station.
4.9C auses of Lining Failure
Most liningf ailures are the result of the misuse of the tank lining, which
results in blistering, cracking, hardening or softening, peeling, staining,
burning, and undercutting. Afrequent causeoffailure is overheating during
operation. When aheavilypigmented surfaceorthick film begins to shrink,
stresses are formed on the surfacethat result in cracks. These cracks do not
always expose the substrate and may not penetrate. Under these conditions,
the best practice is to remove thesea reas and recoat according to standard
repair procedures.
Aging or poor resistance to the corrosive can result in hardening or
softening. As the coating ages, particularly epoxy and phenolic amines,
it becomesb rittle and may chip from the surface. Peeling can result from
improperly cured surfaces, poor surfacepreparation, or awet or dry surface.
Staining results when there is areaction of the corrosive on the surfaceofthe
lining or slight staining from impurities in the corrosive. The true cause must
be determined by scraping or detergent washing the lining.I ft he stain is
removed and softening of the film is not apparent, failure has not occurred.
Liquid-Applied Linings
83
CAT8247—CHAPTER 4—17/10/2006—14:33—SRIDHAR—XML MODEL B–pp. 69–174