Blind Flange Design Calculations - By Abdel Halim Galala

DESIGN CALCULATIONS OF HEAT EXCHANGER

Page : 76 of 136

According to ASME Code, Sec. VIII, Div. 1, Edition 2001, Addenda 2002 / TEMA "R" 7th Edition 88. Designed by : Eng. Abdel Halim Galala, Galala, Design General Manager (Assistant)

Sheet : 1 of 6 Rev. : 0

Project : Design & Fabrication of Heat Exchanger for APRC Refinery Job No. : 7443-33 Dwg. No. : 7443-33-1A 7443-33-1A,, Rev. 0 Exchanger : Residue Cooler, Type : AES, AES, TEMA class class : R

Date : 4.7.2003 Location : Alex. Client : APRC

Sheet : 14

Item : E-323A/B & E-514C/D

P. Flat Unstayed Circular Blind Flange(Channel Cover) Thickness (item no. 22)

[UG-34 & Fig. UG-34 Sketch (j)]

[Attached by Bolts] Blind Cover Material, Clad Metal : SB171 UNS No. C63000

Subjected to internal pressure

Stud bolt material Design Temperature Min. Design Metal T emperature, MDMT Bolt-up and Gasket Seating T emperature Assume corrosion allowance, C Operating Pressure (tube side) Internal Design Pressure, P (MAWP) Allowable Stress of Bolt Material, SB :

[UG-25]

ASME SA266 Class 2 SA 193 Grade B7 o F 140 60 o 53.6 F 12 o F 86 30 0.19685 INCH 5 56.8182 PSIG 4 71.7082 PSIG 5.04826

o

C C o C MM o

2

Kg/CM G 2

Kg/CM G 2

* at design temp.(operating condition), Sb * or at atmospheric temp./bolt-up temp. (gasket seating), Sa Allowable Stress of Flange Material : * at design temp.(operating temp.(operating condition), SfH

25000 25000

PSIG PSIG

1760 1760

Kg/CM G

20000

PSIG

1408

Kg/CM G

* or at atmospheric temp./bolt-up temp. (gasket seating), SfC

20000

PSIG

1408

Kg/CM G

INCH INCH INCH

28 685 623

MM MM MM

INCH

25.4

MM

355.4832 9953.528 563 482.6

MM

2

Kg/CM G 2 2

[Table 1A , SubPart 1 , ASME Sec. II , Part D]

Joint efficiency, E

1

Bolt Hole, Flange outside diameter, A Bolt circut diameter (B.C.D.),

1.10236 26.9685 24.5276

Fig. UG-34, Sketch (j) Figure (5)

No. of bolts Nominal bolt dia., dB Actual cross-sectional area of each bolt, Total actual cross-sectional area of bolts, Ab Flange face outer diameter Flange face inner diameter

28 1 [TEMA Table D-5]

0.551 15.428 22.1654 19

INCH

2

INCH

2

INCH INCH

2 2

MM

MM MM


Page : 77 of 136



Project : Design & Fabrication of Heat Exchanger for APRC Refinery Job No. : 7443-33 Dwg. No. : 7443-33-1A, 7443-33-1A, Rev. 0 Exchanger : Residue Cooler, Type : AES, AES, TEMA class class : R


Sheet : 14

Item : E-323A/B & E-514C/D

P. Flat Unstayed Circular Blind Flange (Channel Cover) Thickness (item no. 22) ( cont.) [Attached by Bolts]


Gasket Details: - Flat metal, jacketed asbestos filled, soft copp[er or brass - Outside diameter - Inside diameter = O.D - 2N - Width, N Gasket Dimensions: Basic gasket seating width, bO = N/2 [Table 2-5.2] Since bo > 1/4 ", Eff ective gasket seating width, b = 0.5 SQRT(bO) Gasket Factor, m Min. Seating Stress, y Facing Sketch

0.125 22.0472 20.8661 0.59055

INCH INCH INCH INCH

3.175 560 530 15

MM MM MM MM

0.29528

INCH

7.5

MM

INCH

6.90 6.9010 108 87 MM

[Table 0.2717

3.5 6500 PSIG (1a); Column II

457.6

21.5039

INCH

546 546.19 .1978 MM

Factor depending upon method of attachment of head, C [Fig. UG-34, Sketch (j)] 0.3 [Table 2-5.2] Gasket moment arm, hG = (B.C.D - d)/2 = (C-G)/2 1.51185

INCH

38.40109 MM

[Table 2-5.1] [Table 2-5.1] [Table 2-5.1]

Diameter at location of gasket load reaction, d ( d represnts G ) When bo is larger than 1/4", d = O.D.of gasket contact face - 2 b

2

Kg/CM G

[Appendix 2-3]

Calculating the Min. required Thickness of Blind Flange, t: t =d

3

CP/SE +1.9WhG /SEd

[UG-34(c)(2)]

When using this formula, the thickness t shall be calculated for both operating conditions, conditions, and gasket seating, seating, and the greater of the two values shall be used.

SA 193 Grade B7 o F 100 140 PSI 25000 ? ASME SA266 Class 2 o F 100 140 20000 ? PSI

150 25000 200 20000


Page : 78 of 136





Sheet : 14

Item : E-323A/B & E-514C/D



Calculating the total bolt load, W (for circular heads): 1. For operating conditions, the value of P shall be the design pressure, and the value of S at the design temperature and W from Formula (3) of 2-5(e) shall be used. Flange Design Bolt Load for circular heads, W [Appendix 2-5(e)] (3) For operating conditions, W = Wm1 2 Wm1 = H + Hp = 0.785 G P + (2b x 3.14 GmP) (1) [Appendix 2-5( 35243.2

lb

159 15986.0 86.05 5 Kg

Flange thickness

0.85602

INCH

21.7 21.743 430 01 MM

0 20000

PSIG PSIG

0 1408

lb

540 54089.0 89.04 4 Kg

t = d

C P / S E + 1. 9 9W Wh G / S Ed Ed^ 3

2. For gasket seating, P equals zero, and the values of S at atmospheric atmosphe ric and W from Formula (4) of 2-5(e) shall be used. [UG-34(c)(2)]

P S Flange Design Bolt Load for circular heads, W [Appendix 2-5(e)] For gasket seating, W = 0.5(Am + Ab) Sa (4)

2

Kg/CM G 2

Kg/CM G

Total required cross-sectional area of bolts, Am = Max (Am1,Am2) Required bolt load under atmospheric temp.conditions, Wm2 = 3.14bGy

(2) 119246

* Total cross-sectional area of bolts at root of thread requiired at operating conditions , Am1 = Wm1/ Sb

1.40973

INCH

2

909.4991 MM2

* Total cross-sectional area of bolts at root of thread required gasket seating, Am2 = Wm2/ Sa

4.76983

INCH

2

3077.304 MM2

4.76983

INCH

2

3077.304 MM2

252473

lb

114 114519. 519.9 9 Kg

1.29857

INCH

32.9 32.983 837 72 MM

1.29857 1.29921 2.00787

INCH INCH INCH

32.9 32.983 837 72 MM 33 MM 51 MM

2.48031 2.48 031

INCH

63

Total required cross-sectional area of bolts, Am = Max (Am1,Am2) For gasket seating,

W = 0.5(Am + Ab) Sa

t = d

(4)

C P / S E + 1. 9 Wh Wh G / S Ed Ed^ 3

t = max. of t of operating and gasket seating Use t without corrosion allowance Use t for construction including R.F. N.B. Che Check ck which which the defle deflection ction is conside considered red a gover governing ning thick thickness ness or not. not. The deflection is ehe governing thickness

MM


Page : 79 of 136





Sheet : 14

Item : E-323A/B & E-514C/D



CONCLUSION: FLANGE SUMMARY Flange thickness (without C.A.) Use t for construction including R.F. For a proper design of flange : 1. You have to make a check for flange deflection.

1.29857 2.04724

INCH INCH

32.9 32.983 837 72 MM 52 MM

GASKET SUMMARY Gasket width, N Required cross-sectional of bolts, Am Actual cross-sectional area of bolts, Ab

0.59055 4.76983 15.428

INCH 2 INCH

15 MM 2 3077.304 MM 2 9953.528 MM

BOLT SUMMARY No. of bolts Size of bolt (the bolt size is represented by its actual cross-sectional area) Bolt hole dia. Total required cross-sectional area of bolts, Am Total actual cross-sectional area of bolts, Ab Actual cross-sectional area of bolt, [TEMA TABLE D-5]

28 1 1.125 4.76983 15.428 0.551

Bolt

0.75 4.76983 8.456 0.302

INCH 2 INCH 2 INCH 2 INCH

NA

1.22047 0.81 0. 8125 25 1.0625 1.125 1.25

INCH INC IN CH INCH INCH INCH

31 20.6 20 .637 375 5 26.9875 28.575 31.75

INCH

2

INCH INCH 2 INCH INCH

2

INCH

2

25.4 28.575 3077.304 9953.528 355.4832

MM MM 2

MM

2

MM

2

MM

Since the actual bolt area Ab > The required bolt area Am Am,, the bolts are adequately enough. N.B. Wh Whe en using bolt with size Total required cross-sectional area of bolts, Am Total ctual cross-sectional area of bolts, Ab Actual cross-sectional area of bolt, [TEMA TABLE D-5] Since the actual bolt area Ab < The required bolt area Am Am,, the bolts are in inadequately adequately enough. Edge distance, E from drawing = 1/2 (A - C) Min in.. Edg dge e di dist stan ance ce,, E (f (fo or bol oltt si size ze 0.7 .75" 5")) Min. Edge distance, E (fo forr bolt size 1") Min. edge distance, E (for bolt size 1-1/8") [TEMA Table D-5] Min. Edge distance, E (for bolt size 1.25")

MM MM MM MM MM


Page : 80 of 136





Sheet : 14

Item : E-323A/B & E-514C/D



Actual Bolt spacing, B (c/c) from drawing Min. Bolt spacing, B (for bolt size 0.75") Min. Bolt spacing, B (for bolt size 7/8") [TEMA Table D-5] Min. Bolt spacing, B (for bolt size 1") Min. Bolt spacing, B (for bolt size 1-1/8") Min. Bolt spacing, B (for bolt size 1-1/4") Max. Recommended bolt spacing, Bmax = 2 d B + 6 t / (m + 0.5) [TEMA 0.5) [TEMA RC

2.74622 1.75 2.0625 2.25 2.5 2.8125 3.94882

INCH INCH INCH INCH INCH INCH

69.75387 44.45 52.3875 57.15 63.5 71.4375 100.3

MM MM MM MM MM MM MM

0.03 0.02 0. 025 5 20

INCH INC IN CH INCH

0.762 0.63 0. 635 5 508

MM MM MM

G = Gasket load reaction diameter as defined by the Code 21.5039 E = Modulus of elasticity at design temperature [ASME Sec.II,Part D, TM 31460000 T = Thickness under consideration (minus groove and C.A.) 1.29921 P = Design pressure 71.7082

INCH PSI INCH PSIG

546 546.19 .1978 MM

SB = Allowable bolting stress at design temperature (Wm1) AB =Actual total cross-sectional root area of bolts hG = Radial distance from diameter G to bolt circle

PSIG 2 INCH

Check for Flat Channel Cover Deflection

[TEMA RCB- 9.21 9.21 ]

The effective thickness of a flat channel cover shall be the thickness at the bottom of the pass partition groove (or the face if there is no groove) minus corrosion allowance in excess of groove depth. The thickness is to be at least that required by the appropriate Code formula and thicker if required to meet proper deflection criteria. The recommended limit for channel cover deflection is: 0.03" for nominal diameters thru 24" 0.1 .125 25% % of nom omin ina al dia diam mete ters rs (n (no omin ina al dia diam mete ter/ r/80 800 0) fo for lar larg ger siz izes es Nominal diameter = Shell ID + 2 ts A method for calculating of channel cover deflection at the center, Y is: G 3 Y = 0.0435G P+0.5SB A B h G 3 ET

(

Where

INCH

)

If the calculated deflection is greater than the recommended limit, the deflection may be reduced by acceptance methods such as: (a) Increase channel cover thickness by the cube root of the ratio of calculated deflection to the recommended recommended limit. (b) Use of strong backs. backs. (c) Change type of construction. Note: For single pass channels, or others in which there is no pass partition gasket seal against the the channel cover, no deflection criteria criteria need be considered.

25000 15.428 1.51185

INCH

2

2214784.07 Kg/CM G

33 5.04826

Kg/CM G

MM

25000

Kg/CM G

2 2

2

9953.528 MM 38.4 38.401 010 09 MM


Page : 81 of 136




Date : 4.7.2003 Location : Alex.

Client : APRC

Sheet : 14

Item : E-323A/B & E-514C/D


The calculated deflection is

G

(0.0435 G


)

0.10054

INCH

2.55 2.5537 379 95 MM

0.03

INCH

0.762

2.88948

INCH

73.3 73.392 928 85 MM

0.00914

INCH

0.23 0.2321 214 49 MM

1.88283

INCH

47.824

0.03303

INCH

0.83 0.8390 905 54 MM

3. Recommended Recommended deflection limit

0.03

INCH

0.762

MM

4. Compare the calculated deflection with the recommended deflection

OK

The minimum thickness of channel cover at bottom of pass partition is The thickness neglecting corrosion allowance is

1.88283 1.88976

INCH INCH

47.824 48

MM MM

Conclusion : Checking of Deflection The min. thickness of channel cover to resist the internal pressure is Where the min. thickness of channel cover to avoid deflection is The min. thickness of channel cover as derived from drawings is The flange thickness increased by

1.33858 1.88976 1.9685 0.07874

INCH INCH INCH INCH

34 48 50 2

MM MM MM MM

Tthickness including groove depth ( 5 MM) Overall thickness including raised faces & groove depth

2.08661 2.48031

INCH INCH

53 63

MM MM

Max. Working Pressure, MWP at New (cold) & Operating (corroded) 2 2 3 at New (cold) P = SE t /d c - 1.9 W h G / d c

104.094

PSIG

2 7.328196 Kg/CM G

104.094

PSIG

2 7.328196 Kg/CM G

Y

=

E T

3

3

P

+

0.5 S

B

A

B

h

G

The recommended deflection limit

MM

Since the calculated deflection exceeds the recommended recommended deflection, we have to increase the flange tickness by the cubic root of the ratio of deflections, Tassumed = T

Y

G =

E T

3

+ 3

Ycalculated Yrecommended

(0.0435 G

3

P

+

[TEMA RCB-9.21]

0.5 S

B

)

ABh G

Easier approach : 1. Assume T, 2. Find Calculated deflection

Y

at Operating (corroded)

G =

E T

3

(0.0435 G

2

2

3

P

+

0.5 S

B

)

ABh G

3

P = SE t /d c - 1.9 W hG / d c

MM

Blind Flange Design Calculations - By Abdel Halim Galala

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