# CHAPTER 9: VALVE DIAGRAMS AND VALVE GEARS¶

## Example 9.5 Page 150¶

In [1]:
#initialisation of variable
from math import pi,sqrt,acos,asin,atan,cos,sin,tan
p=20#in
l=100#in
r=120#r.p.m
v=3.5#in
l2=1#in
l3=1/8#in
v1=1.44#omega in/sec

#CALCULATIONS
V=p*(1.06/1.166)#omega in./sec
R=(V/v1)#omega in/sec

#RESULTS
print"The ratio of velocity of the piston to the velocity is",round(R,3),"Omega in/sec"

The ratio of velocity of the piston to the velocity is 12.626 Omega in/sec


## Example 9.7 Page 151¶

In [2]:
#initialisation of variable
from math import pi,sqrt,acos,asin,atan,cos,sin,tan
v=0.6#in
m=1.0#in
t=0.75#in
p=4#in

#CALCULATIONS
D=t/m#in
A=(p*m/D)#in

#RESULTS
print"the travel and laps of the value is",round(A,3),"in"

the travel and laps of the value is 5.333 in


## Example 9.10 Page 154¶

In [3]:
#initialisation of variable
from math import pi,sqrt,acos,asin,atan,cos,sin,tan
l=1.5#in
p=4.0#in
v=0.98#in

#CALCULATIONS
T=(l*p/v)#in

#RESULTS
print"the particulars of a value and it eccentric is",round(T,3),"in"

the particulars of a value and it eccentric is 6.122 in


## Example 9.12 Page 156¶

In [4]:
#initialisation of variable
from math import pi,sqrt,acos,asin,atan,cos,sin,tan
p=1/10#in
v1=3/4#in
v2=3/5#in
m=1*1/2#in
l=4#cranks
a1=1.25#in
a2=0.7#in

#CALCULATIONS
C=a1/a2#in
A=l*a1/a2#in
S=(A/2-a1)#in

#RESULTS
print"the travel of the value is",round(S,3),"in"

the travel of the value is 2.321 in


## Example 9.17 Page 161¶

In [5]:
#initialisation of variable
from math import pi,sqrt,acos,asin,atan,cos,sin,tan
v=3*1/2#in
a=30#degree
l=0.8#in
v1=0.2#in
L=0.13#in
m=1.075#in
d=0.58#in
p=1.875#in

#CALCULATIONS
V=(p-d)#in
P=V+1.25#in

#RESULTS
print"the main value and the maximum opening to steam is",round(P,3),"in"

the main value and the maximum opening to steam is 2.545 in