Calculations to check whether R-pad is necessary for the below conditions: Operationg Pressure of the Dish Inside Radius of the vessel
2
= =
142.23 39.37
= = = =
39.37 19912 1.00 8.86
=
19912
Psi
= = = = = = = =
19912 0.354 0.315 17.72 0.00
Psi In. In. In.
0.79
In.
tr
=
0.141
In
0.064
trn
=
0.064
In
1.0
fr1
=
1.0
f r2 = (lesser(S n,Sp) / Sv )
1.0
fr2
=
1.0
fr2= S p / Sv
1.0
fr2
=
1.0
Correcton Factor ,F =
1.0
F
=
1.0
(Rn + tn + t) =
9.5
Rn+tn+t
=
9.5
A
=
2.50
A1
=
3.78
A2
=
0.40
Inside Dia.of the major Axis (Ellip.Head) Allowable stress of of vessel Dish Joint Efficiency Inside Radius of the nozzle
P = Rv =
10 Kgs/cm 1000 mm
D= Sv =
1000 mm 14 kgf/mm 1.0 225 mm
E = Rn = Sn =
Allowable stress nozzle nozzle material
Sp = Allowable stress of of Reinforcement Reinforcement plate Nominal thickness of the Dish taken t= tn= Nominal thickness of the nozzle taken Inside diameter of the nozzle d= corrosion allowance c= distance nozzle projects beyond the inner or h= outer surface of the vessel wall Fillet cover weld
leg=
14 14 9 8 450 NIL 2.5 t = 2.5 tn =
2
kgf/mm
2
kgf/mm mm mm mm 0.89 0.79
10
Psi In. Psi In.
0.39
Required Thickness of shell,t r tr = P D / (2S v E-0.2P) =
0.141
Required Thickness of nozzle shell,t n trn = P Rn / (Sn E-0.6 P) Strenth Reduction Factor,f r f r1 = Sn / Sv
=
=
Total C/S Area of Reinforcement required A= d tr F + 2 tn tr F(1-f r1)
2.50
d or (Rn + tn + t) use larger value Tota Totall area area avai availb lbal ale e in she shell ; larg larger er valu value e A1=d (E1t-Ftr ) - 2 t n (E1t-Ft r ) (1-f r1) =
Total area available in nozzle projecting outw A2 = 5 (t n-trn) f r1 t =
small 0.49
A2
=
0.19
A2 = 2 (t n-trn) (2.5 tn+ e) f r1 tn =
0.19
Area available in inward nozzle A3 = 2 (t n-c) f r1 h =
0.62
A3
=
0.62
Area available in outward weld 2 A41= (leg) f r2 =
0.16
A41
=
0.16
Area available in outward weld 2 A42= (leg) f r3 =
0.16
A41
=
0.16
Area available in inward weld 2 A43= (leg) f r1 =
0.16
A43
=
0.16
A5 = (Dp-d-2 Tn) Te Fr3 =
2.08
A5
=
2.08
A1+A2+A3+A41+A42+ A43+A5 =
7.82
Sn =
Allowable stress nozzle material Allowable stress of Reinforcement plate Nominal thickness of the Dish taken Nominal thickness of the nozzle taken Inside diameter of the nozzle corrosion allowance distance nozzle projects beyond the inner or outer surface of the vessel wall Fillet cover weld Nominal thickness of the R-pad Outside diameter of the R-pad
