Customer: Alderley/MOQ DOC.
:NE-N445-13-MDC-01
DESIGN OF DAVIT (30" MANWAY)
Equipment: Horz. Gas Floatation Unit
Ref: Pressure Vessel Design Manual by Dennis Moss
Symbol Values Unit Description Allowable Formulae Result
W 250 Kg Load
Cv 1.5 Vertical Impact factor
fv 375 Kg Vertical Load on davit W x Cv
Dop 60.30 mm OD of davit rod
Tp 7.65 mm Thk of davit pipe
A 521.00 mm
B 0.00 mm
L1 521.00 mm Boom Length SQRT(A2+B2)
L2 451.00 mm Intermediate Support to Top
R 250.00 mm Radius of davit bend
Zp 14846.2097675 mm3 Section Modulus of davit pipe p/32x(Dop3)
M1 195375.0000 Kg.mm Moment at support fv x L1
I 447613.2188 mm4 Moment of Inertia of pipe p/64x(Dop4)
fa 0.1313 Kg/mm2 Axial stress on davit pipe fv/(p/4(Dop2)
M2 87074.0022 Kg.mm Mom. at Tanline of davit bend M1(L2-R)/L2
a 2.1032 Co-efficient (ref. DRMoss pp 293) TpR/(Dop/2)2
b 0.1902 Co-efficient (ref. DRMoss pp 293) 6/(5+6a2)
K 0.8573 Co-efficient (ref. DRMoss pp 293) 1-9/(10 + 12a2)
fb1 13.1599 Kg/mm2 Bending at M1 M1/Zp
fb2 6.0372 Kg/mm2 Bending at M2 M2.Dp/(2I) x 2/(3K(3b)½)
Faa 10.5400 Kg/mm2 Allowable tensile stress for pipe
Sya 25.4900 Kg/mm2 Allowable yield stress of davit pipe
Fba 16.8234 Kg/mm2 Allowable bending stress for pipe 0.6 x Sya
S1 0.7947 Combined Stress at M1 1 fa/Faa +fb1/Fba SATISFACTORY
S2 0.3713 Combined Stress at M2 1 fa/Faa +fb2/Fba SATISFACTORY
EYE BOLT CALCULATION :
Eye bolt material : SA 320 L7
Eye bolt diameter (d) : 25 mm
Yield strength of Eye bolt : 73.9 Kg/mm2
Allowable tensile stress (Ft) = (0.6 x yield) = : 44.34 Kg/mm2
Maximum load in tension (fv) : 375 Kg
Tensile stress in eye bolt = ftb = fv/ [ pi/4 * (d2) ] : 2.44 Kg/mm2
ftb < Ft, hence SAFE
1 of 3
Customer: Alderley/MOQ DOC.:NE-N445-13-MDC-01
DESIGN OF DAVIT (30" MANWAY)
Equipment: Horz. Gas Floatation Unit
EYE BOLT CLIP CALCULATION ON DAVIT :
Dim. A1 : 40 mm
Diameter of Davit rod (Dop) : 80 mm
weld size B1 : 30 mm
Section Modulus of Weld = Zw = 1/6*Dop*B1^2 : 12000.00 mm3
Maximum load at davit clip (fv) : 375 Kg
Yield Strength of weld : 24.60 Kg/mm2
Allowable bending stress (Fb) = (0.66 x yield) = : 16.24 Kg/mm2
Induced stress due to bending = fb = P * A1 / Zw : 1.25 Kg/mm2
EYE BOLT CLIPS CALCULATION ON FLANGE :
`A3' `t1'
`A2'
`Ø d2'
`B2'
Thickness of clips welded to flange ( t1 ) : 16 mm
Holde diameter in clips (d1) : 24 mm
Dimension A2 : 30 mm
Dimension A3 : 70 mm
Fillet weld size (B2) : 10 mm
Maximum load on clips (fv) : 375 Kg
Material of clips : SA 516 GR 70
Yield Strength of clip material : 26.70 Kg/mm2
Allowable shear stress (Fsc) = (0.4 x yield) = : 10.68 Kg/mm2
Induced stress in clips due to shear = fsc = P / [ 2 * ( 2 * t1 * (A2 - d1/2) ) ] : 0.33 Kg/mm2
Allowable tensile stress (Ftc) = (0.6 x yield) = : 16.02 Kg/mm2
Induced tensile stress in clips = ftc = P / [ 2 * t1 ( A3 - d1 ) ] : 0.25 Kg/mm2
Allowable bearing stress in clips (Fbe) = (0.8 x yield) = : 21.36 Kg/mm2
Induced bearing stress in clips = fbe = P / ( t1 * d1 ) : 0.98 Kg/mm2
Allowable shear stress in the weld (Fsw) = (0.4 x yield) = : 10.68 Kg/mm2
Induced shear stress in clips weld = fsw = P / (B2*0.7*2*A3) : 0.38 Kg/mm2
EYE BOLT PIN CALCULATION DUE TO SHEAR :
Material of eye bolt pin : SA 193 Gr L7
Yield Strength of pin : 73.9 Kg/mm2
Diameter of pin (d2) : 24 mm
Cross sectional area of pin (Ap) = (pi)/4 * d22 : 452.39 mm2
Allowable shear stress (Fsp) = (0.4x yield strengh) : 29.56 Kg/mm2
Induced stress in pin due to shear = fsp = fv / Ap*2 : 1.66 Kg/mm2
2 of 3
Customer: Alderley/MOQ DOC.:NE-N445-13-MDC-01
DESIGN OF DAVIT (30" MANWAY)
Equipment: Horz. Gas Floatation Unit
CALCULATION FOR GUIDE SUPPORTS :
Ø `d3'
HOLE
=
A5
=
` '
`L4' `A4'
=
3
`A6'
L '
=
`
t
`2'
`B3'
Dim. L3 : 350 mm
Dim. L4 : 70 mm
Dim. A4 : 70 mm
Dim. A5 : 120 mm
Guide support thickness - t2 : 40 mm
Hole dia in guide supports - d3 : 82 mm
Fillet weld size (B3) : 20 mm
Radial force at guide and support (Fr) = M1/L3 : 558.21 Kg
Material of guide supports : SA 516 GR 70
Yield Strength of clip material : 26.70 Kg/mm2
Allowable shear stress (Fsg) = (0.4 x yield) = : 10.68 Kg/mm2
Induced shear stress in guide supports = fsg = Fr / [ 2 * ( 2 * t2 * (A4 - d3/2) ) ] : 0.12 Kg/mm2
Induced shear stress in weld = fgw = Fr / [ 2 * 0.7 * B3 * A5 ] : 0.17 Kg/mm2
3 of 3
`t1'
`A2'
`d1'
`B2'
4 of 3
`t1'
`A2'
`d1'
`B2'
5 of 3
Customer: PETROFAC/ADCO DOC.:MC-09-006-01V-04V
DESIGN OF DAVIT (36" MANWAY)
Equipment: LP STRIPPER COLUMN REV. : C
Symbol Values Unit Description Allowable Formulae Result
W 850 Kg Load
Cv 1.5 Vertical Impact factor
fv 1275 Kg Vertical Load on davit W x Cv
Do 138.22 mm OD of davit Pipe Di 168.3
Tp 15.04 mm Thk of davit pipe
A 537.00 mm
B 326.00 mm
L1 628.00 mm Boom Length SQRT(A2+B2)
L2 595.00 mm Intermediate Support to Top
R 300.00 mm Radius of davit bend
Zp 208760.589037 mm3 Section Modulus of davit pipe p/32x(Dop3)
M1 800700.0000 Kg.mm Moment at support fv x L1
I 21466267.8609 mm4 Moment of Inertia of pipe p/64x(Dop4)
fa 0.1761 Kg/mm2 Axial stress on davit pipe fv/(p/4(Dop2)
M2 396985.7143 Kg.mm Mom. at Tanline of davit bend M1(L2-R)/L2
a 19.9468 Co-efficient (ref. DRMoss pp 293) TpR/(Dop/2)2
b 0.0025 Co-efficient (ref. DRMoss pp 293) 6/(5+6a2)
K 0.9981 Co-efficient (ref. DRMoss pp 293) 1-9/(10 + 12a2)
fb1 3.8355 Kg/mm2 Bending at M1 M1/Zp
fb2 9.8413 Kg/mm2 Bending at M2 M2.Dp/(2I) x 2/(3K(3b)½)
Faa 10.5400 Kg/mm2 Allowable tensile stress for pipe
Sya 25.4900 Kg/mm2 Allowable yield stress of davit pipe
Fba 15.2940 Kg/mm2 Allowable bending stress for pipe 0.6 x Sya
S1 0.2675 Combined Stress at M1 1 fa/Faa +fb1/Fba SATISFACTORY
S2 0.6602 Combined Stress at M2 1 fa/Faa +fb2/Fba SATISFACTORY
EYE BOLT CALCULATION :
Eye bolt material : SA 320 B8
Eye bolt diameter (d) : 30 mm
Yield strength of Eye bolt : 35.15 Kg/mm2
Allowable tensile stress (Ft) = (0.6 x yield) = : 21.09 Kg/mm2
Maximum load in tension (fv) : 1275 Kg
Tensile stress in eye bolt = ftb = fv/ [ pi/4 * (d2) ] : 1.70 Kg/mm2
ftb < Ft, hence SAFE
`A1'
1
`d'
Customer: PETROFAC/ADCO DOC.:MC-09-006-01V-04V
DESIGN OF DAVIT (36" MANWAY)
Equipment: LP STRIPPER COLUMN REV. : C
EYE BOLT CLIP CALCULATION ON DAVIT :
`A1'
1
`d'
`B1'
Dim. A1 : 60 mm
Diameter of Davit rod (Dop) : 100 mm
Fillet weld size B1 : 12 mm
Section Modulus of Weld = Zw = PI/4*Dop2*B1 : 65973.45 mm3
Maximum load at davit clip (fv) : 1275 Kg
Yield Strength of weld : 24.60 Kg/mm2
Allowable bending stress (Fb) = (0.66 x yield) = : 16.24 Kg/mm2
Induced stress due to bending = fb = P * A1 / Zw : 1.16 Kg/mm2
EYE BOLT CLIPS CALCULATION ON FLANGE :
`A3' `t1'
`A 2'
`Ød2'
`B2'
Thickness of clips welded to flange ( t1 ) : 20 mm
Holde diameter in clips (d1) : 32 mm
Dimension A2 : 35 mm
Dimension A3 : 70 mm
Fillet weld size (B2) : 15 mm
Maximum load on clips (fv) : 1275 Kg
Material of clips : SA 516 GR 65
Yield Strength of clip material : 24.60 Kg/mm2
Allowable shear stress (Fsc) = (0.4 x yield) = : 9.84 Kg/mm2
Induced stress in clips due to shear = fsc = P / [ 2 * ( 2 * t1 * (A2 - d1/2) ) ] : 0.84 Kg/mm2
Allowable tensile stress (Ftc) = (0.6 x yield) = : 14.76 Kg/mm2
Induced tensile stress in clips = ftc = P / [ 2 * t1 ( A3 - d1 ) ] : 0.84 Kg/mm2
Allowable bearing stress in clips (Fbe) = (0.8 x yield) = : 19.68 Kg/mm2
Induced bearing stress in clips = fbe = P / ( t1 * d1 ) : 1.99 Kg/mm2
Allowable shear stress in the weld (Fsw) = (0.4 x yield) = : 9.84 Kg/mm2
Induced shear stress in clips weld = fsw = P / (B2*0.7*2*A3) : 0.87 Kg/mm2
EYE BOLT PIN CALCULATION DUE TO SHEAR :
Material of eye bolt pin : SA 193 Gr B7
Yield Strength of pin : 52.73 Kg/mm2
Diameter of pin (d2) : 30 mm
Cross sectional area of pin (Ap) = (pi)/4 * d22 : 706.86 mm2
Allowable shear stress (Fsp) = (0.4x yield strengh) : 21.09 Kg/mm2
Induced stress in pin due to shear = fsp = fv / Ap*2 : 3.61 Kg/mm2
Customer: PETROFAC/ADCO DOC.:MC-09-006-01V-04V
DESIGN OF DAVIT (36" MANWAY)
Equipment: LP STRIPPER COLUMN REV. : C
CALCULATION FOR GUIDE SUPPORTS :
Ø `d3'
HOLE
=
A5
=
` '
`L4' `A4'
=
3
`A6'
L '
=
`
t
`2'
`B3'
Dim. L3 : 300 mm
Dim. L4 : 80 mm
Dim. A4 : 80 mm
Dim. A5 : 160 mm
Guide support thickness - t2 : 30 mm
Hole dia in guide supports - d3 : 102 mm
Fillet weld size (B3) : 15 mm
Radial force at guide and support (Fr) = M1/L3 : 2669 Kg
Material of guide supports : SA 516 GR 65
Yield Strength of clip material : 24.60 Kg/mm2
Allowable shear stress (Fsg) = (0.4 x yield) = : 9.84 Kg/mm2
Induced shear stress in guide supports = fsg = Fr / [ 2 * ( 2 * t2 * (A4 - d3/2) ) ] : 0.77 Kg/mm2
Induced shear stress in weld = fgw = Fr / [ 2 * 0.7 * B3 * A5 ] : 0.79 Kg/mm2
138.22
4512
15.04
90000
`t1'
`A2'
`d1'
`B2'
`t1'
`A2'
`d1'
`B2'
Customer: PETROFAC/ADCO DOC.:MC-09-006-01V-04V
DESIGN OF DAVIT (30" MANWAY)
Equipment: LP STRIPPER COLUMN REV. : C
Symbol Values Unit Description Allowable Formulae Result
W 450 Kg Load
Cv 1.5 Vertical Impact factor
fv 675 Kg Vertical Load on davit W x Cv
Dop 75.00 mm OD of davit rod
Tp 0.00 mm Thk of davit pipe
L1 541.00 mm Boom Length
L2 520.00 mm Intermediate Support to Top
R 300.00 mm Radius of davit bend
Zp 41417.4812729 mm3 Section Modulus of davit pipe p/32x(Dop3)
M1 365175.0000 Kg.mm Moment at support fv x L1
I 1553155.5477 mm4 Moment of Inertia of pipe p/64x(Dop4)
fa 0.1528 Kg/mm2 Axial stress on davit pipe fv/(p/4(Dop2)
M2 154497.1154 Kg.mm Mom. at Tanline of davit bend M1(L2-R)/L2
a 0.0000 Co-efficient (ref. DRMoss pp 293) TpR/(Dop/2)2
b 1.2000 Co-efficient (ref. DRMoss pp 293) 6/(5+6a2)
K 0.1000 Co-efficient (ref. DRMoss pp 293) 1-9/(10 + 12a2)
fb1 8.8169 Kg/mm2 Bending at M1 M1/Zp
fb2 13.1067 Kg/mm2 Bending at M2 M2.Dp/(2I) x 2/(3K(3b)½)
Faa 10.5400 Kg/mm2 Allowable tensile stress for pipe
Sya 25.4900 Kg/mm2 Allowable yield stress of davit pipe
Fba 15.2940 Kg/mm2 Allowable bending stress for pipe 0.6 x Sya
S1 0.5910 Combined Stress at M1 1 fa/Faa +fb1/Fba SATISFACTORY
S2 0.8715 Combined Stress at M2 1 fa/Faa +fb2/Fba SATISFACTORY
