TUBESHEET THICKNESS CALCULATION PER UHX (SECTION VIII DIV 1)
UHX-12.5.1 STEP 1. DETERMINE Do, u, u*, AND hg' FROM UHX-11.5.1
Do ro dt Equivalent diameter of outer tube limit circle ro=radius to outermost tube hole center dt=nominal outside diameter of tubes 14.1674
Do
ro dt
6.7087 0.75
p
1
tt
0.083
Et
27000000
E
28300000
St
17100
S
20000
ltx h
1.6929 1.811
UL1 LL1
1.4961 14.1732
hg Ct
0.1969 0.125
Gs
17.6
Gc
17.6
200.7152228
Do2
p dt p
u=basic ligament efficiency for shear p=tube pitch u
0.25
Et St ; dt 2t t Effective tube hole diameter E S
d * MAX dt 2t t
tt=nominal wall tube thickness Et=modulus of elasticity for tube material at tubesheet design temperature E=modulus of elasticity for tubesheet material at material at tubesheet design temperature St=allowable St=allowable stress for tube material at tubesheet design temperature S=allowable stress for tubesheet material at tubesheet design temperature p=tube expansion depth ratio=ltx/h ltx=expanded lenght of tube in tube sheet h=tubesheet thickness q 0.93478741 Factor 1 0.610937597 Factor 2 0.584 d* 0.610937597 p*
p 1/ 2
4 MI N A L ; ( 4 Dop) 1 Do 2
Effective tube pitch
AL=total area of untubed untubed lanes=(UL1*LL1)+(UL2*LL2)+(UL lanes=(UL1*LL1)+(UL2*LL2)+(UL3+LL3) 3+LL3)
AL 21.20452452 4Dop 56.6696 Factor1 21.20452452 p* 1.074912994 u*=(p*-d*)/p*
Effective ligament efficiency for bending
u* 0.431639955 hg'= hg'=MA MAX X((hg ((hg-C -Ct) t);0 ;0)) )) Effe Effect ctiv ive e tube tube sid side e pass pass par parti titi tion on gro groov ove e dept depth h hg=tube side pass partition groove depth Ct=tubesheet corrosion allowance on the tube side Factor1 0.0719 Factor2 0 hg' 0.0719
UHX-12.5.2 STEP 2. CALCULATE DIAMETER RATIOS ps=Gs/Do Gs=Diameter of shell gasket load reaction pc=Gc/Do Gc=Diameter of channel gasket load reaction ps 1.242288634 pc 1.242288634
UL2 LL2
UL3 LL3
MTS=Do2/16*((ps-1)(ps2+1)*Ps-(qc-1)(qc2+1)*Pt)) Ps=Design Pressure shell side Pt=Design Pressure tube side
Moment due to pressures Ps and Pt acting on the unperforated tubesheet rim Ps 480 Case 1 (Ps=0) Pt 470 Case 2 (Pt=0) Case 3 (Use Ps and Pt)
MTS 77.30146541 Case 3 MTS -3633.16887 Case 1 MTS 3710.47034 Case 2 UHX-12.5.3 STEP 3. CALCULATE h/p. IF q CHANGES RECALCULATE d* AND u* h/p 1.811 RECALCULATE d* AND u* Factor 1 0.480589 Factor2 0.584 d* 0.584 u* 0.456700213 Determine E*/E and v* relative to h/p from UHX-11.5.2
E*
E*/E v*
0.54 0.31
A
16.063
15282000
Configuration d Proceed to step 5 UHX-12.5.5 STEP 5. CALCULATE DIAMETER RATIO K K=A/Do A=Outside diameter of tubesheet K 1.133800133 Calculate coefficient F F=((1-v*)/E*)*(ElnK) F 0.160456868 UHX-12.5.6 STEP 6. FOR EACH LOADING CASE CALCULATE MOMENT M* M*=MTS+((Gc-Gs)/(2piDo))Wmax M* 77.30146541 Case 3 M* -3633.16887 Case 1 M* 3710.47034 Case 2 UHX-12.5.7 STEP 7. Mp AND Mo. Mp=(M*-(Do2/32)F(Ps-Pt))/(1+F) Mo=Mp+(Do2/64)*(3+v*)(Ps-Pt) Mp 57.94015254 Case 3 Mp 474.2348487 Case 1 Mp 349.6817375 Case 2
Mo Mo Mo
161.747557 Case 3 4821.00785 Case 2 5040.69556 Case 1
M 161.7475568 Case 3 M 4821.007848 Case 2 M 5040.695558 Case 1 UHX-12.5.8 STEP 8. CALCULATE THE TUBESHEET BENDING STRESS Sigma=(6M)/(u*(h-hg')2 (h-hg')2 3.02446881 Sigma 702.6008244 Sigma 20941.54716 Sigma 21895.82906
Assumed thickness is acceptable if Sigma<=2S Case 3 Case 1 Case 2
THE ASSUMED THICKNESS IS ACCEPTABLE THE ASSUMED THICKNESS IS ACCEPTABLE THE ASSUMED THICKNESS IS ACCEPTABLE
UHX-12.5.9 STEP 9. CALCULATE THE AVERAGE SHEAR STRESS IN THE TUBE SHEET Tau=(1/4u)(Do/h)*(Ps-Pt) Tau 78.22970734 Tau 3676.796245 Tau 3755.025953
Assumed thickness is acceptable if Tau<=0,8S Case 3 THE ASSUMED THICKNESS IS ACCEPTABLE Case 1 THE ASSUMED THICKNESS IS ACCEPTABLE Case 2 THE ASSUMED THICKNESS IS ACCEPTABLE
TAG TYPE AET 30"x240"
CUSTOMER TUBESHEET THICKNESS CALCULATION PER UHX (SECTION VIII DIV 1)
UHX-14.5.1 STEP 1. DETERMINE Do, u, u*, AND hg' FROM UHX-11.5.1
Do ro dt Equivalent diameter of outer tube limit circle ro=radius to outermost tube hole center dt=nominal outside diameter of tubes Do
24.812
Do2
ro dt
12.031 0.75
p
1
tt
0.109
Et
27740000
E
27740000
St
22280
S
30900
ltx h
2.85 3
UL1 LL1
1.375 25.25
hg Ct
0.1875 0.125
Nt
444
615.635344
p dt p
u=basic ligament efficiency for shear p=tube pitch u
0.25
Et St ; dt 2t t Effective tube hole diameter E S
d * MAX dt 2t t
tt=nominal wall tube thickness Et=modulus of elasticity for tube material at tubesheet design temperature E=modulus of elasticity for tubesheet material at material at tubesheet design temperature St=allowable stress for tube material at tubesheet design temperature S=allowable stress for tubesheet material at tubesheet design temperature p=tube expansion depth ratio=ltx/h ltx=expanded lenght of tube in tube sheet h=tubesheet thickness q 0.95 Factor 1 0.600673528 Factor 2 0.532 d* 0.600673528 p*
p 1/ 2
4 MI N A L ; ( 4 Dop) 1 Do 2
Effective tube pitch
AL=total area of untubed lanes=(UL1*LL1)+(UL2*LL2)+(UL3+LL3)
AL 34.71875 4Dop 99.248 Factor1 34.71875 p* 1.037963892 u*=(p*-d*)/p*
Effective ligament efficiency for bending
u* 0.421296317 hg'=MAX((hg-Ct);0)) Effective tube side pass partition groove depth hg=tube side pass partition groove depth Ct=tubesheet corrosion allowance on the tube side Factor1 0.0625 Factor2 0 hg' 0.0625 Calculate ao, ps, pc, xs and xt ao=Do/2 ao ps=as/ao as=Gs/2 as ps 1.25745607 pc=ac/ao ac=Gc/2 ac pc 1.25745607 xs=1-Nt(dt/2ao)2 xs 0.594321537 xt=1-Nt((dt-2tt)/(2ao))^2 xt 0.795881349 UHX-14.5.2 STEP 2.
12.406 15.6 Configuration d
15.6 Configuration d
UL2 LL2
UL3 LL3
CALCULATE SHELL COEFFICIENTS Bs,ks,Ls,@s CALCULATE CHANNEL COEFFICIENTS Bc,kc,Lc,@c For configuration d and B all these c oefficients are 0
Ps=Design Pressure shell side Pt=Design Pressure tube side
Gs
31.2
Gc
31.2
Ps Pt
500 Case 1 (Ps=0) 640 Case 2 (Pt=0) Case 3 (Use Ps and Pt)
UHX-14.5.3 STEP 3. CALCULATE h/p. IF q CHANGES RECALCULATE d* AND u* h/p 3 RECALCULATE d* AND u* Factor 1 0.278442718 Factor2 0.532 d* 0.532 u* 0.487458086 Determine E*/E and v* relative to h/p from UHX-11.5.2 E*/E v*
0.47 0.315
Lt
239.5
Using the calculated value of Xa. Determine Zd, Zv and Zm from Fig UHX-13.2 Zd Zv Zm
0.097 0.1413 0.6148
E*
13037800
Calculate Xa Xa=(24*(1-v*2)Nt*Et*tt*(dt-tt)ao2)/(E*L*h3)^1/4 L=Lt-2h L 233.5 Xa 2.429419581
UHX-14.5.4 STEP 4. CALCULATE DIAMETER RATIO K AND COEFFICIENT F K=A/Do A=Outside diameter of tubesheet
A
32.25
ws
0
wc
0
K 1.299774303 Calculate coefficient F F=((1-v*)/E*)*(ElnK) F 0.382128906 Calculate phi and Q1 phi=(1+v*)F phi 0.502499511 Q1=(ps-1-phiZv)/(1+phiZm) Q1 0.14244607
UHX-14.5.5 STEP 5 Calculate ws, ws* and wc, wc* ws=psksBs@s(1+hBs)=0 For d and B configuration ws*=(ao2(ps2-1)(ps-1)/4)ws* 5.757436277 wc=pckcBc@c(1+hBc) wc 5.757436277 Calculate Yb Yb=(Gc-Gs)/Do Yb
0
UHX-14.5.6 STEP 6. FOR EACH LOADING CASE CALCULATE EFFECTIVE PRESSURE Pe=Ps-Pt Pe Pe Pe
-140 Case 3 -640 Case 1 500 Case 2
UHX-12.5.7 STEP 7. FOR EACH LOADING CASE CALCULATE Q2 Q2=(ws*Ps-wc*Pt)+Yb*W/2pi)/(1+phiZm)
Q2 -615.798365 Case 3 Q2 -2815.07824 Case 1 Q2 2199.279873 Case 2 For Pe<>0 calculate Q3 Q3=Q1+(2Q2/Peao2) Q3 0.199604059 Case 3 Q3 0.199604059 Case 1 Q3 0.199604059 Case 2 Using Xa and Q3 determine coefficient Fm for each loading case from Figs. UHX-13.3-1 and UHX-13.3.2 Fm Calculate bending stress sigma Sigma=(1,5Fm/u*)*(2ao/h-hg')^2Pe Sigma 5225.14963 Case 3 Sigma 23886.39831 Case 1 Sigma 18661.24868 Case 2
0.17
Assumed thickness is acceptable if Sigma<=2S THE ASSUMED THICKNESS IS ACCEPTABLE THE ASSUMED THICKNESS IS ACCEPTABLE THE ASSUMED THICKNESS IS ACCEPTABLE
Calculate average shear stress Tau Tau=(1/4u)(ao/h)*(Pe) Tau 1157.893333 Tau 5293.226667 Tau 4135.333333
Assumed thickness is acceptable if Tau<=0,8S Case 3 THE ASSUMED THICKNESS IS ACCEPTABLE Case 1 THE ASSUMED THICKNESS IS ACCEPTABLE Case 2 THE ASSUMED THICKNESS IS ACCEPTABLE
