API 650 Flashcards
AST fabricated to API 650 is normally designed not to exceed an operating temperature of:,,,,,,,,,,
93 C or (200 F)
- Minimum size of fillet welds in the construction or repairs of an AST built to API Standard 650 is:
On plates 5 mm (3/16 in.) thick………….
plates more than 5 mm (3/16 in.) thick,,,,,,,,,,,,
- full fillet weld
- fillet weld thickness shall not less than 1/3 of thinner plat and shall be 5 mm (3/16”)
- As per API Standard 650, the overlap at lap-welded joints shall be at least five times the nominal thickness of the thinner plate, but need not exceed,
1” for single-welded lap joints
2” for double welded lap joints
Single-welded lap joints are permissible only on ,,,,,,,,,,,,,,,
bottom plates and roof plates.
Calculation of Design Thickness by the 1-Foot Method shall not be used for tanks ,,,,,,,,,,,,,,
- larger than 61 m
- (200 ft) in diameter
Vertical joints in adjacent shell courses shall ,,,,,,,,,, but shall be offset from each other a minimum,,,,,,,,
not be aligned,
distance of 5t
In an AST built to API Standard 650, the bottom annular plates have radial weld joints, and are single butt welded with permanent back-up bar, in which case, the extent of radiography of radial joints shall be,
one spot radiograph shall be taken on 50 % of the
radial joints
Personnel who perform and evaluate radiographic examinations according to this section shall be qualified and certified by the Manufacturer as meeting the requirements of certification as generally outlined in ,,,,,,
Level II or Level III of ASNT SNT-TC-1A
Per API 650, calculation of shell thickness by the 1-foot method cannot be used for tanks:
larger than 61 m (200 ft) in diameter.
API 650 applies only to tanks whose entire bottom is uniformly supported and to tanks in ,,,,,,,,,,,, service that have a maximum design temperature of ,,,,,,,,,,,,,
non-refrigerated
93 °C (200 °F) or less
API 650 code is tank construction code for
approximating atmospheric pressure
Bottom Plates:
All bottom plates shall have a corroded thickness of not less than ,,,,
5 mm (3/16 in.)
Bottom Plates:
The terms “Sketch plates” and “annular plates” refer to Plates in :
Tank bottom
Bottom Plates:
all rectangular and sketch plates (bottom plates on which the shell rests that have one end rectangular) shall have a nominal width of ,,,,,,,,,,,,,,
not less than 1800 mm (72 in.).
Bottom Plates:
Plates of sufficient size shall be ordered so that, when trimmed, at least a ,,,,,,,,,,,,width will project outside the shell
50 mm (2 in.)
Bottom Plates:
Unless otherwise specified on the Data Sheet, Line 12, tank bottoms requiring sloping shall have a minimum
slope of ,,,,,,,,,,,,,upwards toward center of the tank
1:120
Hydrostatic testing of tank shells is:
Basically water fill test
Internal inspection of tanks during shut-down is essentially for inspection of:
Tank bottom
During tank inspection, the inspector should be more strict while inspecting:
The shell vertical welds
Since the tank is neither a pressure vessel, nor the piping, the welding procedures and welders for API 650 tanks are qualified as per:
ASME IX
,,,,,,,,,,,,,,, is/are mandatory appurtenances for Storage tanks
Tank vents
API 650 covers:
Cylindrical, welded, above ground tanks only
Maximum design internal pressure in an AST referred to by API 650 and API 653 is
Not exceeding 2.5 psig
Design Metal Temperature*: Enter either lowest 1-day mean temperature plus ………….
8 ºC (15 ºF)
