This document discusses the relationship between valve opening percentage and flow for an equal percentage valve. It provides the formula Q = Q0 * e^bY, where Q is the flow, Q0 is the initial flow, Y is the valve opening percentage, and b is a constant determined by the maximum flow. The document then applies this formula using sample values and graphs the resulting flow at each 10% valve opening from 10-100%.

1. Equal percentage of valve &
opening VS flow
Prem Baboo
Sr. Manager (Prod)
National Fertilizers Ltd. India
F.I.E., Institution of Engineers (India)
Technical Advisor & an Expert for
www.ureaknowhow.com

2. Formula is Q = Q0
eby
For Typical values of
Q0 1000
Qmax
= 30000
Substituting these values in the above equation we can
get
30000 = 1000 X eb x1
e b x 1 = 30
there fore b= ln (30)
b= 3.4011974

3. Stroke% y value Flow to %y Flow in kg/hr
10 0.1 Q10 1404.94759
20 0.2 Q20 1973.87773
30 0.3 Q30 2773.19476
40 0.4 Q40 3896.1933
50 0.5 Q50 5473.94739
60 0.6 Q60 7690.6092
70 0.7 Q70 10804.9029
80 0.8 Q80 15180.3222
90 0.9 Q90 21327.5572
100 1 Q100 29964.1

4. 1,405
1,974
2,773
3,896
5,474 7,691
10,805
15,180
21,328
29,964
0
5000
10000
15000
20000
25000
30000
35000
1 3 5 7 9
Flowkg/hr
Stroke%/10