Existing:
5.5 DIMENSIONAL TOLERANCES
5.5.1General
The purpose of the tolerances given in 5.5.2 through 5.5.6 is to produce a tank of acceptable appearance and to permit proper functioning of floating roofs. These tolerances may be waived by agreement between the purchaser and the manufacturer.
Proposed Change:
5.5.1 General
The purpose of the tolerances given in 5.5.2 through 5.5.6 is to produce a tank of acceptable appearance and to permit proper functioning of floating roofs. These tolerances may be waivedmodified by agreement between the purchaser and the manufacturer.
NOTE TO REVIEWERS: SEE FOLLOWING PAGE FOR PROPOSED REVISIONS TO APPENDIX L. /

AGENDA ITEM 650-547

Sheet 1 of 1

Revision 3

May 6, 2003

Title: Revised Tank Tolerances

Source: George Morovich e-mail

Purpose: To permit the purchaser to propose tighter roundness tolerances for new tanks. The existing 650 standard only specifies radial tolerances at the base of the tank (1’ above the bottom corner weld). The proposed revisions would allow the purchaser to specify additional radial limits throughout the shell height and/or specify tighter plumbness limits, thereby reducing the out-of-roundness of new tanks.

Contact: John Farrell

BP
Phone: 630 434-6564
Fax: 630 493-3713
Email:
Background: API 653 specifies radial tolerances throughout the height of the tank, while API 650 simply specifies a limit at 1’ above the corner weld. Therefore, we now may have tighter roundness limits on reconstructed tanks than new tanks. This change would tighten 650 roundness limits.
Technical Justification: Setting tighter limits on roundness would likely improve the performance of floating roofs and floating roof seals and simplify the construction of floating roofs, seals and aluminum domes. It also would reduce the likelihood of local buckling that can occur when an out-of-round tank is filled for the first time and thus eliminate the future need to repair these buckles.
Cost Effects: There could be some extra cost for shell erection. These added costs will be at least partially offset by the reduced cost(s) of the floating roof, floating roof seal and/or aluminum dome installations. This will also reduce the likelihood of incurring costs associated with reworking the shell after a hydrotest.

APPENDIX L

API Standard 650DATE

Storage TankBY

Data Sheet FILE NO.

PAGE ______1______OF ___4______

GENERAL INFORMATION (TO BE COMPLETED BY PURCHASER)

1.PURCHASER/AGENT

ADDRESS ______CITY ______STATE ______ZIP CODE ______PHONE

2.USER______

3.ERECTION SITE: NAME OF PLANT______

LOCATION ______

4.TANK NO. ______MAXIMUM CAPACITY (3.2.5.1) ______m3 (bbl)NET WORKING CAPACITY m3 (bbl) OVERFILL PROTECTION (API-2350) ______m (bbl) OR ______mm (in.)

5.PUMPING RATES:IN ______m3/h (bbl/h)OUT m3/h (bbl/h)

6.MAXIMUM OPERATING TEMPERATURE ______°C (°F)

7.PRODUCT STORED ______DESIGN SPECIFIC GRAVITY _____ AT°C (°F)

DESIGN METAL TEMPERATURE ______°C (°F)VAPOR PRESSURE kPa (in. water)

8.CORROSION ALLOWANCE:SHELL ______mm (in.)ROOF mm (in.)

BOTTOM ______mm (in.)STRUCTURALS mm (in.)

9.SHELL DESIGN:q BASIC STANDARD 650q APPENDIX Aq APPENDIX F

DESIGN PRESSURE ______kPa (lbf/in.2)

10.ROOF DESIGN:q BASIC STANDARD 650q APPENDIX C (EXTERNAL FLOATING)

q APPENDIX G (ALUMINUM DOME)q APPENDIX H (INTERNAL FLOATING)

FRANGIBLE ROOF JOINT?q YESq NO

11.ROOF DESIGN INFORMATION:

UNIFORM LIVE LOAD kPa (lbf/ft2)

SPECIAL LOADS (PROVIDE SKETCH) kPa (lbf/ft2)

INSULATION LOAD kPa (lbf/ft2)

MAXIMUM DESIGN ROOF TEMPERATURE °C (°F)

GASES IN THE VAPOR SPACE

12.EARTHQUAKE DESIGN?q YESq NO (APPENDIX E)ROOF TIE RODS (3.10.4.5)? q YESq NO

SEISMIC ZONE ______IMPORTANCE FACTOR

ZONE FACTOR (TABLE E-2) ______SITE COEFFICIENT (TABLE E-3) 13. WIND LOAD: VELOCITY km/h (mph)

PROVIDE INTERMEDIATE WIND GIRDER (3.9.7)? q YESq NO

14.ENVIRONMENTAL EFFECTS:MAXIMUM RAINFALL mm/h (in./h)

TOTAL SNOW ACCUMULATION mm (in.)

15.SIZE RESTRICTIONS:MAXIMUM DIAMETER ______m (ft)MAXIMUM HEIGHT m (ft)

16.FOUNDATION TYPE:q EARTH q CONCRETE RINGWALL q OTHER

17. OPTIONAL DIMENSIONAL TOLERANCES (See sec. 5.5 for basic limits) :

MAXIMUM OUT-OF-PLUMBNESS: ______mm (in.) TO BE MEASURED AND RECORDED AT FOLLOWING SHELL HEIGHTS: ______m (ft.)

MAXIMUM RADIAL TOLERANCE : +/______mm (in) TO BE MEASURED AND RECORDED AT FOLLOWING SHELL HEIGHTS: ______m (ft.)

REMARKS