quality bulletin _november 22, 2013

8/13/2019 Quality Bulletin _November 22, 2013

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QUALITY BULLETIN

Friday, November 22th

, 2013

1. API 650 Welded Steel Tan! For "il Stora#e

1. $eneral

This standard covers material, design, fabrication, erection and testing requirements for

vertical, cylindrical, aboveground, closed and open top welded steel storage tanks in various

sizes and capacities for internal pressure approximating atmospheric pressure.

The tanks shall have entire bottom uniformly supported, non-refrigerated, and maximum

operating temperature of 2 !.

2. %aterial!

"ost common plates used for the construction shall be #$T" #2%&, #&' or any suitable

higher strength carbon steel plate as desired.

(ormal design metal temperature shall be assumed to be )* ! above the lowest ) day mean

ambient temperature in the locality where the tank is to be installed.

+late used for the reinforcement of the opening shall be of the same material as the shell

plate to which it is installed. t shall be as thick as the primary plate. $hell nozzle and man-

way material shall be equal or greater strength and of compatible material.

+late manufacturer shall submit the mill test data including the toughness at design metal

temperature.

!or materials with minimum tensile strength less than , psi , manual shielded metal

arc welding electrodes shall conform to xx series.


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PT. Tetra Pak Stainless Equipment Jl. Raya Pulo Gebang Km.3 Cakung Jakarta 13950, IndonesiaTelp. +62-21 48700967 (Hunting)Tetra Pak Internal

3.1 &oint!

Tack welds are not considered to have strength value.

!ull fillet welds are required for plates of &/)' in 0*mm1 thick. +lates with thickness more

than * mm, the weld shall not be less than )/& of the thinner plate thickness at the oint, but

not less than * mm.

$ingle lap welds are used for bottom and roof plate welds. 3ap weld oints shall not be less

than *t of the thinner plate but need not be more than ) in 02* mm1.

4ertical shell oints shall be butt oints with complete penetration and fusion that provides

the same quality of deposited metal on both inside and outside the weld surface. 4ertical

oints in adacent shell courses shall not be in alignment. #n offset of at least *t shall be

adopted, where t is the thicker plate thickness at the oint.

5orizontal $hell oints shall be similar to vertical oint. The top angles shall be oined by

double lap weld.

6utt weld full penetration bottom oint shall be used normally with the annular ring. #

minimum of 2 in 0* mm1 proection beyond outside edge of shell shall be provided.


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3.2 &oint '(ontd.)

$hell to bottom fillet weld shall not be more than 7 in 0)2 mm1 if the shell is )2 mm or less.

t shall be less than t, the thinner section at the oint. "inimum two weld passes are

required.

8oof and top angle oints shall be welded with continuous full fillet weld. Top angle

0horizontal leg1 may extend either inside or outside.

*. +ottom Plate

6ottom plate shall be of at least 9 in 0' mm1, exclusive of any corrosion allowance. t shall

proect at least ) in 02* mm1 beyond outside edge of the shell.

&.* #nnular 6ottom +lates

This shall be at least 2: in 0' mm1 wide. The 2 in 0* mm1 proection beyond outside shell

surface is required.


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5. Shell e!i#n

This shall involve calculation for required 0designed1 shell thickness td 0including corrosion

allowance for design product, adoption of the nominal thickness of shell t, material selection

of the tank, and adopting allowable stress.

;here td is designed shell course thickness 0assumed to be ) ft above the bottom line of the

shell course1 in inch, < is the tank diameter in ft, 5 is the height of the product level from

the bottom line of the shell course in ft, = is specific gravity of product stored, $d is the

design allowable stress in psi and ># is the corrosion allowance for the full life of the tank.

tt is the thickness required for the hydro test condition for the particular shell course, and $t

is the allowable stress at the hydro test condition and temperature. These formula are

allowed for shell diameter less than 2 ft.

6. Shell "-enin#!

"an-way necks, nozzle necks, and shell plate opening shall be uniform and smooth, with

rounded corners. (o reinforcement is generally required for nozzles 2 in and smaller.

+ermanent attachment welds shall not be closer than & in from horizontal shell oint seams,

nor closer than ' in from vertical oints, insert plate oints or reinforcement plate fillet welds.

&.) 8oofs

8oof plates shall be &/)' in 0* mm1 minimum. $elf supported roof may require thicker plate.

$upported cone roof plate shall not be rigidly attached to supporting members.

8oof plate shall be attached to the top angle. $upported cone roof slope shall be ? in 02

mm1 in )2 in 0& mm1.

8afters shall be spaced so that in the outer ring, their centers are not more than '.2% ft

0)%% mm1 measured along the circumference. The maximum spacing of the inner ring

rafters is *.* ft 0)'* mm1.

8oof columns can be steel pipe, which has to be sealed with provision of draining and

venting.


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. Wind /oad on Tan!

@verturning stability shall be checked. ;ind velocity is assumed as ) mph 0)' km/hr1.

The wind load on vertical surface may be assumed as & lb/sq ft. 3oad on proected

cylindrical area shall be )% lb/sq ft. #nchor spacing shall be maximum ) ft apart.

. Weldin#

#cceptable weld processes shall beA

- $hielded metal arc

- =as metal arc

- !lux-cored arc

- $ubmerged arc

- lectro-slag

The welding may be performed manually, automatic, semi-automatic. The quality assurance

shall be as per #$" +4 >ode, ;elding, $ec B.

.1. Weldin# Preation!

;elding shall not be done on moist or wet surfaces

t shall not be performed in high wind conditions 0unless protected, shielded1

f the metal temperature is -&2 ! and t exceeds ).2* in 0&2 mm1, preheating is required.

"ulti-layer welds require removal of slag and deposits before next layer is welded.

#ll weld edges must merge with plate surface without sharp angle.

"aximum acceptable undercut in vertical oint shall allowed up to )/': in 0.: mm1 and

)/&2 in 0.% mm1 for horizontal butt oints.

Tack welds shall be removed before finishing the oint.

3ow hydrogen electrode shall be used for $"#; process for welds )2 mm and thick.

.2. Shell eldin#

"isalignment in completed vertical oint over */% in 0)' mm1 thick shall not exceed )C of

plate thickness with a maximum of .)2* in 0& mm1. !or less thick oints it shall be limited to

.' in 0).' mm1.

Doints over ).* in 0& mm1 thick shall have the weld pass not exceeding ? in 0)% mm1 and

minimum pre-heat shall be 2 ! 0) >1.

;elds attaching nozzles, man-ways, other openings shall be visually examined followed by

"+ or +T after the stress relief treatment but before hydro test.


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$hell to bottom weld shall be checked visually followed by "+ or +T, diesel test or right

angle vacuum test. #lternate method shall be pressure testing the volume between the

inside and outside welds to )* psi 0) bar1 applying soap solution to the face of fillet weld.

Tank bottom shall be tested using vacuum box, tracer gas test or external float test or

combination of them.

8einforcing pad shall be pneumatic pressure tested with )* psig pressure between shell and

reinforcement on each opening.

4. imen!ional Tolerane!

The maximum out of plumb ness of the top relative to bottom of shell may not exceed )/2

of the total tank height.

>oncrete ring walls shall be level within E/- )/% in 0& mm1 any & ft circumference and within

' mm in total circumference, measured from average elevation.

10. adio#ra-hi

10.1. ertial Shell Weld!7

6utt welds ) mm and thinner, one spot in first ) ft of each type and thickness and for

each welder and thereafter one additional spot in each additional ) ft. #tleast 2*C of

the spots shall be at unctions of verticals and round seam oints, minimum two per tank.

#dditional one spot in each bottom ring vertical.

+lates greater than ) mm to ) in 02* mm1, same as above plus all unctions. #dditional

two spots in all bottom ring verticals.

+lates thicker than ) in 02* mm1, full radiography of all verticals plus all unctions. 6utt

welds around periphery of insert nozzles and man-ways shall be fully radiographed.

10.2. 8ori9ontal Shell Weld!7

@ne spot in first ) ft for all thickness without regard to welder, there after one spot each

additional 2 ft.

10.3. Tan +ottom Annlar rin#7


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11. i!al ae-tane o: de:et

(o visible crater or surface cracks or arc strikes are acceptable.

Fndercut acceptable shall be within limits indicated under *.2.

+orosity acceptable up to a cluster size of &/&2 02.* mm1 in diameter and one in each : in

0) mm 1 length of welds.

12. ;entering and anti- rotation device shall be provided.

!lexible seal between roof periphery and shell shall be provided.


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2. Sy!tem o: Fit! and Tolerane!The standard reference temperature is 2

> for industrial measurements and consequently for

dimensions defined by the system.

quality bulletin _november 22, 2013

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