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Agenda Item 650-714 (Rev. 2)

Title: SPLIT-SEGMENT REPAD DETAILS

Date: November 12, 2012, December 6,2012 (Rev. 2)

Handled By: Ron Bailey American Tank & Vessel, Inc. 15915 Katy Freeway Suite 290 Houston, TX 77094 Telephone: 281-492-7778 Fax: 281-492-7667 Email : ron@at-v.com

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Purpose: CLARIFY PARA.5.7.2.10 AND 5.7.5.1 OF API-650 FOR DETAILS OF SEGMENTED NOZZLE/MANWAY REPADS

Source: D. ROSENKRANTZ EMAIL OF 7-6-10

Discussion:

Both of the referenced paragraphs mention repads of multiple pieces without any detail of seam orientation, seam welding, seam NDE or location of repad test hole.

This item went to Sub Committee Letter Ballot prior to the Fall Meeting 2012 in Los Angeles. The Sub Committee Letter Ballot resulted in several negative votes. Primarily the negative votes wanted the option for segmented repads removed from API-650. Discussion within the Subgroup F&I indicated that no participating user or manufacturer practiced segmented repads on API 650 (new construction) tanks.

Further Discussion: Even though the Subgroup F&I consensus was to remove the segmented repad option from API 650, I still pondered the reason for its origin . Consequently, I reviewed API 650 back to edition number one and the paragraph read identical, the segmented repad option still being in print. However, this paragraph changed in November 1998 in a way that would impact the segmented repad option .

• Agenda Item 650-714 (Rev. 2) page 2 of 2 (Further Discussion Continued)

Upon the issuance of API 650 Tenth Edition, November 1998 the standard removed from the subject paragraph the option to manufacture manways of "press formed" construction. In that type of construction the shell reinforcing plate and the manway neck were one piece pressed from a plate. In order to accomplish this, the manway had to be made in two identical halves requiring "segmented" construction thus requiring a test hole in each half. With the elimination of the "press formed" manway in the API 650 Tenth Edition we should have removed the option of segmented repads. (See attached pages from Ninth Edition API 650 and Tenth Edition API 650.)

Conclusion: Subgroup F&I presents for Sub Committee Letter Ballot Agenda Item 650-714 (Rev. 2) for re-ballot.

Revised Paragraphs in API 650 with words as shown deleted with a line through them or BOLD.

• 5.7.2.10 Reinforcing plates for shell openings or eaoh se9ment of tAo plates if they are not maGo in one pieoe shall be provided with a 6mm (1/4 in .) diameter telltale hole. The holes shall be located on the horizontal centerline and shall be open to the atmosphere.

5.7.5.1 Shell manholes shall conform to Figures 5-7A and 5-7B and Tables 5-3a through 5-5b (or Tables 5-6a through 5-Bb), but other shapes are permitted by 5.7.1.B. Manhole reinforcing plates or eaoh se9ment of the plates if they are not maGe in one pieoe shall be provided with a 6 mm (1/4 in .) diameter telltale hole (for detection of leakage through the interior welds). The hole shall be located on the horizontal centerline and shall be open to the atmosphere.

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~70 ~ , 14 __ _

.:..-3._12 _____________ AP_I_St_AN_DAR_ D_6_SO_ ...Jlt-.lfH \Z~ITloN '. \.LL-( Iqtj3 ation at lower temperatures for longer periods of time in ac· cordance with the following tabulation:

Metal Temperatw'e (degrees Fahrenheit)

1100 1050 1000 950

900 (minimum)

Holding Time (hours per inch of thickness)

1 2 3 5

10

For intennediate temperatures, the time of heating shall be determined by straight·line interpolation.

3.7.4.3 When the shell material is Group I, II, III, or IIIA, all opening connections 12 inches or larger in nominal diam· eter in a shell plate or thickened insert plate more than I inch thick shall be prefabricated into the shell plate or thickened insert plate, and the prefabricated assembly shall be ther· mally stress relieved at a temperature of IIOO°F-1200°F for I hour per inch of thickness prior to installation. The stress· relieving requirements need not include the flange·ta-neck welds or other nozzle·neck and manhole·neck attachments, provided the following conditions are fulfilled:

a. The welds are outside the reinforcement (see 3.7.2.3). b. The throat dimension of a fillet weld in a slip·on flange does not exceed * inch, or the butt joint of a welding-neck flange does not exceed * inch. If the material is preheated to a minimum temperature of 200°F during welding, the weld limits of * inch and % inch may be increased to 1* and 1M inches, respectively.

3.7.4.4 When the shell material is Group IV, IVA, V, or VI, all opening connections requiring reinforcement in a shell plate or thickened insert plate more than M inch thick sil!UI be prefabricated into the shell plate or thickened insert plate, and the prefabricated assembly shall be thermally stress relieved at a temperature of ll00"F-1200°F for I hour per inch of thickness prior to installation.

When connections are installed in quenched and tempered material, the thermal stress-relieving temperature shall be 50°F (±50°F) lower than the tempering temperature and shall not exceed II OooE The holding time shall be I Iiour per inch of thickness. The stress-relieving requirements do not apply to the weld to the bottom annular plate, but they do apply to flush·type cleanout openings when the bottom rein-forcing plate is an annular-plate section. The stress-relieving requirements need not include the flange-to-neck welds or other nozzle-neck and manhole-neck attachments, provided the conditions of 3.7.4.3 are fulfilled .

10), but other shapes are permitted by 3.7.1.8. Manhole rein-forcing plates or each segment of the plates if they are not made in one piece shall be provided with a "-inch-diameter telltale hole (for detection of leakage through the interior welds). Each hole shall be located on the horizontal center-line and shall be open to the atmosphere.

3.7.5.2 Manhole frames may be press formed or may be of built-up welded construction. The dimensions listed in Ta-bles 3-3 through 3-7 cover both types of construction. The dimensions are based on the minimum neck thicknesses listed for the built-up type and allow for the thinning of the neck in the pressing operation of the formed type.

3:7.5.3 The maximum diameter of a shell cutout shall be the sum of the inside diameter of the frame plus two times the attachment-flange thickness plus the outside-corner radius (see Figure 3-4B). Dimensions are listed in the tables for a pressed frame using a constant-diameter ring die and for a built-up frame. The latter dimensions apply conservatively to a pressed frame using a constant-diameter plug die.

3.7.6 SHELL NOZZLES AND FLANGES

3.7.6.1 Shell nozzles and flanges shall conform to Fig-ures 3-4B, 3-5, and 3·7 and Tables 3-8 through 3-10, but other shapes are permitted by 3.7.1.8. Nozzle reinforcing plates or each segment of the plates if they are not made in one piece shall be provided with a' "-inch-diameter telltale hole. Such holes shall be located substantially on the hori· zontal centerline and shall be open to the atmosphere.

3.7.6.2 The details and dimensions specified in this stan· dard are for nozzles installed with their axes perpendicuiar to the shell plate. A nozzle may be installed at an angle other than 90 degrees to the shell plate in a horizontal plane, pro. vided the width of the reinforcing plate (Wor Do in Figure 3· 5 and Table 3-8) is increased by the amount that the horizontal chord of the opening cut in the shell plate (D, in Figure 3-5 and Table 3-9) increases as the opening is changed from circular to elliptical for the angular installa-tion. In addition, nozzles not larger than 3 inches nominal pipe size-for the insertion of thermometer wells, for sam-pling connections, or for other purposes not involving the at-tachment of extended piping-may be installed at an angle of 15 degrees or less off perpendicular in a vertical plane without modification of the nozzle reinforcing plate.

3.7.7 FLUSH-TYPE CLEANOUT FITTINGS

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3 .. 7.4.5 Inspection after stress relief shall be in accordance With 5.2.3.6. .

3.7.7.1 Flush-type c1eanout fittings shall conform to the requirements of 3.7.7.2 through 3.7.7.12 imd to the details and dimensions shown in Figures 3-9 and 3-10 and Tables 3c II through 3-13. When a size intermediate to the sizes given in Tables 3-11 through 3-13 is specified by the purchaser, the construction details and reinforcements shall conform to the

3.7.5 SHELL MANHOLES

3.7.5.1 Shell manholes shall conform to Figures 3·4A and 3-4B and Tables 3-3 through 3-7 (or Tables 3-8 through 3-

(text continued on page 3-20)

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Notes:

,,=,'10 y 1 l4-

WELDED STEEL TANKS FOR OIL SToRAGE

J~k{ Itft1? tzQ'T1o-J

3-13

20· and 24" sheD manholes: twenty-eight 3/ .. "-diameter bolts In 7/s" holes 30· and 36" shell manholes: forty-two '/ .. "-diameter botts in 7/," holes (Bolt holes shall straddle the flange vertical centerline)

(See Fi ure 3-48)

-,;,Y:~~~-=~-.._ Gasket (see Note 1): ---_______ ~ One 1/ .. " telltale hole in

reinforcing plate, on hOrizontal centerline

Alternative circular shape

It --..,--.,

L

Radius approximately equal to thickness

of bolting flange

See Note 2

"

--1h See

Note 3

Not less than 3Tar 21/2., whichever is smaller

See Figure 3-48

T

--

Detail a

20· manhole: 253/8" 00 x 20· 10 X VI" thickness 24" manhole: 293/8" 00 x 24· 10 x 1/8" thickness 30" manhole: 353/a" 00 x 30" 10 X Va" thickness 36· manhole: 413/." 00 x 36" 10 x 1/1" thickness

Manhole flange shall be shaped to suit tank curvature

-~-1-i D, ~-

1 ~-ei---

1114" Rounded comers (6" minimum radius)

S/a"-diameter rod

'I.

Uniform, smooth surface

1 ID

20M and 24M manhole: 30M

30" manhole: 36" 36- manhole: 42-

(Increase as necessary for clearence: see 3.7.3)

Rounded corne" ! ManhtelD

t

Rounded ManholelD See Figure 3-4

See Nole2

1/4 tn (see Note 4)

I_See Nole3 Sae Note 2

Detail b

t Lt,,(see Note 4) See

Note 5

1-. See Note 3

Detail c

1. Unless otherwise specified. the gasket material shall be fiber sheet. S. The size of the weld shall be equal to the thickness of the thinner member jOined.

2. The gasketed face shaU be machine finished to provide a minimum gasket bearing width of * inch. 3. See Table 3-3; types of flanges and methods for attaching bolting flanges to manhole necks are interchangeable. 4. See Tables 3-4 through 3-7.

6. The shen nozzles shown in Figure 3-5 may be substituted for manholes 20 inches in diameter and larger. 7. When the shell nozzles shown in Figure 3-5 arc used. the minimum cen-terline heights above a tank bottom that are given in Table 3-8 are accept-able.

Figure 3-4A-Shell Manhole

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3-1. API STANDARD 650

500 mm (20') and 600 mm (24') shell manholes: lwenly-eigh12O mJJHIiameter (3/,') bolts In 24 mm (,I.") holes 750 mm (30') and 900 mm (36') shell manholes: forty-two 20 mm-diameter ("I,') bolls In 24 mm ('''') holes (Boll hoi .. shall straddle Ihe liang_ vertical centerline.)

Gasket (see Note 1): 500 mm (20") manhole: 635 mm (25~") 00 x 500 mm (20') 10 x 3 mm ('10") "'ickness IlOO nvn (24') monOOle: 735 mm (29'111 CO x 6110 mm (24') 10 x 3 mm r"1 "'_

(See Fogure 3-4B) 750 mm (3D1 _: 885 mm (35'fo1 00 x 75D mm (3D1 10 x 3 mm ('''') "'1_ ,...--::::-:-==-=;;';::':~~Y::~d~9OD~~mm~(3e~1 _: 11135 mm (41''', 00 x lIDO mm (36') ill x3 """ rio, ,,_

One 6 mm ('I,') 1e111aIe hole In reinforcing plale,

on horizontal centerline

L (see Note 6)

-

a'

i -~ --

I

Reinforcing pad shall be ehaped 10 suit lank curvature

j mm (1'1,') ~---'-+-Rounded comers Rgure 3·48 (150 mm (6'] minfrnum radius)

Smm ('I,')

~ (see Note 4)

500 mm (20') and 600 mm (24') manhole: mm

Rounded

750 mm (30') manhole: 900 mm 900 mm (36") manhole: 1 D50 mm (I","""se as necessary for clearance)

Manhole 10

~t

Lt. (see Note 4) (w See Note 2 I '

'-- If (see Note 3)

( Sae NoIe5 See Note 2 It1

'-- I, (see Note 3)

Detail a

Notes:

• 1. Gasket malerial shaD be specilied by the purchaser. The gaskel malerial shall meel setvice requirements based on product stored, lemperature, and fire resistanCe.

2. The gBSkeled face shall be machine Ilnished 10 provide a mini-mum gaskel.lJeering width 0120 mm (3/4 in.).

3. See Table 3-3. 4. See Table 3-4.

Detail b

5. The size of the weld shall equal the IIlckness of Ihethimer mem-berjolned.

6. The shell nozzles shown in Table 3-8 may be substituted for man-holes.

7. When tIie shell noZZles shown In Rgure 3-5 are used, the mini-mum cenlertine helghls above the lank bottom given In Table 3-8 are acceptable.

B. For dimensions lor Do. 0", L. and W. see Table 3-6, Columns 4, 5, and6.

Figure 3-4A-8hell Manhole

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~D'I . \qqe WEweo STEel TANKS FOR OIL SToRAGE 1$ eJ:::lIT10 N 3-21

Table 3-9--Dimensions for Rush-Type Cleanout Fittings [mm (in.)]

CoIuam 1 Column 2 Column 3 CoIwna4 ColumnS CoIuam6 CWmn7 Column 8 CoIumD9 Column 10 Column 11

ArcWJdth Upper Upper Come< fIaD&e ofSbelI Comer R.Idius of Sbell Edge Width' BotIom

Heigbtof WJdthof Rcinfon:iDg Radiuaof ReiDfun:iDg DistaDce (&ceptat fIaD&e Special Bolt Numla Diametec Opeuing Opening PlaIe Opening PlaIe of Bolla Bottom) Width spocingb of of

h b W 'I '2 • /3 h , BoIIB Doha 200(8) 400 (16) 1170(46) 100 (4) 360 (14) 32(1"") 100(4) !JO (3I,v 80(31,,.) 22 'lJ} (3'0)

600(24) 600(24) 1830(72) 300 (12) 740(29) 40 (I"V 100(4) 9S (ll,.) !JO (3I,v 36 'lJ) (3'0)

900(36) 1200 (48) 2700(106) 4SO" (18) 1040 (41) 40 (1l,v tl5(4"v 120(~',.) 110(4" ,.) 46 24(1)

1:zood(48) 1200 (48) 3200(125) 600(24) 1310 (51"v 40 (I"V 115(4'1,) 115 (S) 115 (4" v 52 24(1)

·po ..... cl< thicJme"" grealD"than 40 mm (19"6 in.).iDcrease/3 .. uecesSOl)' ID provide a 1.5 mill (1"6 in.) clearaDce _ the ROquiled neck-lI>-fIaoge weld aDd the bead of the bo1t. "Rdi:n 10 spacing at the tow .. ......,.. of the c:leaDaat-fiIIing fIaoge.

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