Api 653 Repairs Exam With Detailed Questions and Analyzed Answers
Where to find joint types table - Answer-Api sec. 4, table 4.2
Where to find joint efficiency table - Answer-Api 653 sec. 4, table 4.2
Where to find table for type and extent of radiography performed - Answer-Api 653 sec. 4, table 4.2 and
Api 650 sec. .8.1, fig 8-1
What is the equation for Tmin or max fill height for localized corrosion? Where is it found? - Answer-Api
653 sec.4.
H=(S*E*Tmin)/(2.6*D*G)
What is the equation for Tmin or max fill height for entire shell? Where is it found? - Answer-Api 653,
sec.4
H=(S*E*Tmin)/(2.6*D*G)+1
Lap patch shell repairs are acceptable for what types of tank shells? - Answer-Butt weld, lap weld, and
riveted tank shells
Lap patch repairs are considered permanent and are subject to what? - Answer-Ongoing inspections
Lap patch material shall comply with what requirements? - Answer-The requirements of current
applicable standards of construction and API 653
Lap patch repairs shall not be used on any shell course of what thickness? Nor is it to replace what on
the shell? - Answer-Shall not be used on shell course thicker than 1/2" or to replace door sheets or shell
plates
, Except as permitted by 9.3.3.2 and 9.3.4.3, what thickness material shall a lap patch be? - Answer-Shall
be less than 1/2" or thickness of the shell plate, but not less than 3/16"
What shape can lap patch be? - Answer-Circular, oblong, square, or rectangular. All corners shall be
rounded to a minimum 2" radius. Nozzle reinforcement shapes of API650 figure 5.8 are also acceptable
Can lap patch plate cross butt welded vertical or horizontal shell seams? - Answer-Yes. Seam welds shall
be ground flush and lap patch welds must overlap a minimum of 6" beyond seam.
Weld spacing requirements of figure 9-1 shall be used as a basis for what? - Answer-Locating repair
plates relative to butt welds, fillet welds, or riveted seams.
Can lap patch plates intersect with shell to bottom weld? - Answer-Yes. Vertical sides of lap patch must
intersect shell to bottom weld at 90* angle and shell to bottom weld is in compliance with figure 9.6
Can lap patches on interior of tank shell intersect with shell to bottom weld? - Answer-No. Patch shall be
located a minimum 6" away from shell to bottom weld
What is the maximum vertical and horizontal dimensions of lap patch plate? - Answer-Max vertical is
48". Max horizontal is 72"
What is the minimum dimensions of a lap patch plate? - Answer-4"
Can shell openings and their reinforcements be located within a lapped patch repair? - Answer-No
Before applying lap patch repair, what examination shall be performed? - Answer-Area to be welded
shall be UT'd to examine for defects and thickness
Where to find joint types table - Answer-Api sec. 4, table 4.2
Where to find joint efficiency table - Answer-Api 653 sec. 4, table 4.2
Where to find table for type and extent of radiography performed - Answer-Api 653 sec. 4, table 4.2 and
Api 650 sec. .8.1, fig 8-1
What is the equation for Tmin or max fill height for localized corrosion? Where is it found? - Answer-Api
653 sec.4.
H=(S*E*Tmin)/(2.6*D*G)
What is the equation for Tmin or max fill height for entire shell? Where is it found? - Answer-Api 653,
sec.4
H=(S*E*Tmin)/(2.6*D*G)+1
Lap patch shell repairs are acceptable for what types of tank shells? - Answer-Butt weld, lap weld, and
riveted tank shells
Lap patch repairs are considered permanent and are subject to what? - Answer-Ongoing inspections
Lap patch material shall comply with what requirements? - Answer-The requirements of current
applicable standards of construction and API 653
Lap patch repairs shall not be used on any shell course of what thickness? Nor is it to replace what on
the shell? - Answer-Shall not be used on shell course thicker than 1/2" or to replace door sheets or shell
plates
, Except as permitted by 9.3.3.2 and 9.3.4.3, what thickness material shall a lap patch be? - Answer-Shall
be less than 1/2" or thickness of the shell plate, but not less than 3/16"
What shape can lap patch be? - Answer-Circular, oblong, square, or rectangular. All corners shall be
rounded to a minimum 2" radius. Nozzle reinforcement shapes of API650 figure 5.8 are also acceptable
Can lap patch plate cross butt welded vertical or horizontal shell seams? - Answer-Yes. Seam welds shall
be ground flush and lap patch welds must overlap a minimum of 6" beyond seam.
Weld spacing requirements of figure 9-1 shall be used as a basis for what? - Answer-Locating repair
plates relative to butt welds, fillet welds, or riveted seams.
Can lap patch plates intersect with shell to bottom weld? - Answer-Yes. Vertical sides of lap patch must
intersect shell to bottom weld at 90* angle and shell to bottom weld is in compliance with figure 9.6
Can lap patches on interior of tank shell intersect with shell to bottom weld? - Answer-No. Patch shall be
located a minimum 6" away from shell to bottom weld
What is the maximum vertical and horizontal dimensions of lap patch plate? - Answer-Max vertical is
48". Max horizontal is 72"
What is the minimum dimensions of a lap patch plate? - Answer-4"
Can shell openings and their reinforcements be located within a lapped patch repair? - Answer-No
Before applying lap patch repair, what examination shall be performed? - Answer-Area to be welded
shall be UT'd to examine for defects and thickness
