Ch:10 Pipes and pipe joints

exa 10-1 - Page 295

In [1]:
from math import sqrt
sigta=140/2#
nt=0.75#
#Let the flow rate be Q
Q=0.25#
v=1.2#
D=1.13*sqrt(Q/v)#
D=520#
p=0.7#
C=9#
t=(p*D)/(2*sigta*nt)+C#
print " t is %0.1f mm     "%(t)#

 t is 12.5 mm

exa 10-2 - Page 295

In [2]:
from math import pi,sqrt
p=3*8#
sigta=60#
d=150#
t=d/2*sqrt(((sigta+p)/(sigta-p))-1)#
t=75*sqrt((84/36)-1)#
t=40#
do=d+(2*t)#
D=d+(2*t)+20#
w=10#
Ds=d+(2*w)#
P=pi*(Ds**2)*8/4#
sigp=310#
FOS=4#
sigb=77.5#
At=P/(sigb*2)#
At=1300#
D=250#
db=45#
b=D#
a=1.8*b#
CD=D+(2*db*1.2)#
sigp=310#
Pr=0.75*sigp*At#
Pr=Pr*10**-3#
t=40#
D1=d+(2*t)+20#
D2=D1+(4.6*31)#
CD=D2-((3*t)+20)#
print " Pr is %0.2f kN     "%(Pr)#
print "\n D1 is %0.0f mm     "%(D1)#
print "\n D2 is %0.1f mm     "%(D2)#
print "\n CD is %0.1f mm     "%(CD)#

 Pr is 302.25 kN     

 D1 is 250 mm     

 D2 is 392.6 mm     

 CD is 252.6 mm

exa 10-3 - Page 296

In [3]:
from __future__ import division
from math import sqrt,pi
p=14#
d=50#
sigyp=270#
FOS=3#
sigta=sigyp/FOS#
pt=2*p#
t=d/2*sqrt(((sigta+pt)/(sigta-pt))-1)#
t=10#
D1=d+(2*t)#
Ds=D1+20#
P=pi*(Ds**2)*p/4#
sigba=380/4#
At=P/(4*sigba)#
At=245#
db=20#
Dd=70+(2*20)+5#
R=db+2.5#
B=(Dd/sqrt(2))+(2*(db+2.5))#
B=127#
Y=Dd/(2*sqrt(2))#
Rm=34.12#
M=(P*Y/2)+(P*Rm/pi)#
sigfa=250/5#
b=127/70#
Z=b/6#
tf=sqrt(M/(sigfa*Z))#
tf=44#
print " d is %0.0f mm     "%(d)#
print "\n t is %0.0f mm     "%(t)#
print "\n B is %0.0f mm     "%(B)#
print "\n R is %0.1f mm     "%(R)#
print "\n Y is %0.2f mm     "%(Y)#
print "\n tf is %0.0f mm     "%(tf)#

 d is 50 mm     

 t is 10 mm     

 B is 127 mm     

 R is 22.5 mm     

 Y is 40.66 mm     

 tf is 44 mm

exa 10-4 - Page 297

In [4]:
from math import tan,sqrt,pi
p=1.25#
D=200#
nt=0.75#
C=9#
sigta=20#
t=(p*D)/(2*sigta*nt)+C#
t=18#
D1=D+(2*t)#
dr=D1+10#
sigp=310#
sigba=sigp/4#
db=16#
Db=dr+32+5#
Do=Db+(2*db)#
P=pi*(251+db)**2*1.25/4#
n=6#
Y=(Db-dr)/2#
M=P/n*Y#
Z=dr*tan(30*pi/180)/6#
tf=sqrt(M/(sigta*Z))#
tf=22#
Deff=dr+db+5#
print " D is %0.0f mm     "%(D)#
print "\n t is %0.0f mm     "%(t)#
print "\n Y is %0.1f mm     "%(Y)#
print "\n tf is %0.0f mm     "%(tf)#
print "\n Deff is %0.0f mm     "%(Deff)#

 D is 200 mm     

 t is 18 mm     

 Y is 18.5 mm     

 tf is 22 mm     

 Deff is 267 mm