Mathcad - conflatberekening - Nikhef - conflatberekening.mcd Author: lvdiepen Created Date: 7/1/2005...
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Transcript of Mathcad - conflatberekening - Nikhef - conflatberekening.mcd Author: lvdiepen Created Date: 7/1/2005...
dm4.A 3.5mm:= Minor diameter bolts
kN 1000N:= Conversion factor
p 0.7mm:= Pitch
β 60deg:= apex angle
φ atanp
π dm4.A⋅
:= Pitch angle
φ 3.6 deg=
µk 0.15:= Friction factor
ρ atanµk
cosβ2
:= * Friction angle
ρ 9.83deg=
Nm N m⋅:= Conversion factor
Page No. Report No.
Checked By
Drawing No.
Calculation conflat with pressure load File name: Conflat calculationLHCb VErtex LOcator
23/03/2005Prepared By L van Diepen
INPUT
bar 0.1N
mm2:= Conversion factor
k 1.5:= Safety factor
P 100bar:= Pressure
H2 18.5mm:= Diameter conflat knife
n 6:= Number of bolts
C 500N
mm:= Sealing force (C=300-500N/mm)
Cmin 300N
mm:= Minimum sealing force
dm4 4mm:= Diameter bolts
omtrek 58.1mm= circumferential conflat knife
Fseal C omtrek⋅:= Fseal 2.9 104× N= sealing force in bolts
Fseal.b
Fseal
n:= Fseal.b 4.8 103× N= sealing force per bolt
σFp.b Fseal.b+( )0.25 π⋅ dm4
2⋅:= σ 438.9
N
mm2= tensile stress per bolt
Fb.totaal Fseal.b Fp.b+:=Fb.totaal 5.5 kN= total force per bolt
Max.negative force in m4 bolt (12.9): 6,8 kN
Yield stress of m4 bolt (12.9): 1100 N/mm^2
Bolt strength is sufficient
Pn
M4
H2
CALCULATION
Internal pressurePn k P⋅:= Pn 15
N
mm2=
Pressure loadAp 0.25 π⋅ H2
2⋅:= flange surface
Fp Pn Ap⋅:= Fp 4 103× N= pressure load
Fp.bFp
n:= Fp.b 672 N= force per bolt
Sealing force
omtrek π H2⋅:=
(Leaking test with Helium 100 bara)2.4 10 6−⋅ mbarl
s⋅Leaking rate:
The conflat connection performed well at a pressure of 150 bara (water)
Leak test
Max. Torque on m4 bolt(12.9): 5.2Nm
Total torqueT 4.5 Nm=T Tt Tf+:=
Torque from frictionTf 2.2 Nm=Tf µk Fb.totaal⋅ 1.3⋅dm4
2⋅:=
Torque from turning Tt 2.3 Nm=Tt Fb.totaal tan φ ρ+( )⋅
dm4.A
2⋅
:=
Calculation of torque on the bolts
Fseal Fp− 2.5 104× N=
Fseal Fp− Fseal.min>
Fseal.min 1.7 104× N=Fseal.min Cmin omtrek⋅:=
Minimum Sealing force: