Chapter 15 : Basics of Pneumatics

Example 15.1 Page No 405

In [2]:
import math

#Variable initialization
V1=20.0                 #gal volume
P1=20.0                 #lbf/in^2 pressure
n=2.0

#CALCULATIONS
V2=V1/n
P2=(P1+14.7)*V1*231.0/(V2*231.0)
P3=P2-14.7

#RESULT
print('Guage pressure = %.3f psi ' %P3)

Guage pressure = 54.700 psi

Example 15.2 Page No 406

In [2]:
import math

#Variable initialization
V1=1500.0               #in^3 volume
T=80.0                  #F temperature
T1=200.0                #F temperature

#CALCULATIONS
V2=V1*(460.0+T1)/(T+460.0)

#RESULT
print('Volume the heated gas will occupy = %.3f in ^3 ' %V2)

Volume the heated gas will occupy = 1833.333 in ^3

Example 15.3 Page No 406

In [3]:
import math

#Variable initialization
P1=2000.0           #in^3
T=80.0              #F temperature
T1=250.0            #F temperature

#CALCULATIONS
P2=(P1+14.7)*(460.0+T1)/(T+460.0)
P3=P2-14.7

#RESULT
print(' Guage pressure = %.3f psi ' %P3)

 Guage pressure = 2634.257 psi

Example 15.4 Page No 407

In [1]:
import math

#Variable initialization
P1=2000.0               #lbf/in^2 pressure
V1=1500.0               #in^3 volume
T2=250.0                #F temperature
T1=75.0                 #F temperature
V2=1000.0               #in^3 volume

#CALCULATIONS
P2=(P1+14.7)*V1*(T2+460.0)/((T1+460.0)*V2)
P3=P2-14.7
#RESULT
print('\n Guage pressure = %.3f psi ' %P3)

 Guage pressure = 3995.871 psi

Example 15.5 Page No 409

In [5]:
import math

#Variable initialization
s=10.0                #stroke in
d=2.0                 #in diameter
r=40.0                #cpm cycles per rate
P1=80.0              #lbf/in^2 pressure
Ps1=552+101          #kN/m^2 pressure
Ps2=101              #kN/m^2 pressure
#CALCULATIONS
V1=math.pi*d**2*s*r/(4*1728.0)
V2=(P1+14.7)*V1/14.7
# In SI units
Vs1=(20.3*25.4*r)/(1000000)
Vs2=(Ps1*Vs1)/Ps2
#RESULT
print(' Air consumption in cfm of free air = %.3f cfm free air ' %V2)
print(' In SI units Air consumption in cfm of free air = %.3f m^3/min free air ' %Vs2)

 Air consumption in cfm of free air = 4.685 cfm free air 
 Air consumption in cfm of free air = 0.133 cfm free air