Control valve Flow characteristic. How the equal percentege
curve form?
Answers were Sorted based on User's Feedback
Answer / malaini
Manivannan answer is Linear curve. For equal percentage
every equal control valve opening will give equal
percentage incremental of flow rate. Tq
Is This Answer Correct ? | 11 Yes | 0 No |
Answer / shyam
Through control valve flow characteristic ( cv )
we calculate flow rate at inlet & outlet pressure of
control valve.
Is This Answer Correct ? | 3 Yes | 0 No |
Answer / k.surya mutyalaro
each increment in valve lift increases the flowrate by a
certain percentage of the previous flow. The relationship
between valve lift and orifice size (and therefore flowrate)
is not linear
but it is depends on Valve rangeability (ratio of the
maximum to minimum controllable flowrate)
v(h)=((e power x)/t) * Vmax
V(h)=
Volumetric flow through the valve at lift H.
x
=
(ln t) H Note: 'In' is a mathematical function known as
'natural logarithm'.
t
=
Valve rangeability
H
=
Valve lift (0 = closed, 1 = fully open)
max
=
Maximum volumetric flow through the valve
it is very important that the Valve rangeability defers
from the valve to valve.
Is This Answer Correct ? | 1 Yes | 0 No |
Answer / www.islamqa.com
x-axis is %valve stroke
y-axis is %flow rate
we have 3 versatile characteristics:
====================================
linear: flow rate is linearly proportional with valve stroke
equal percentage: flow rate increases slowly with valve
stroke
quick opening: flow rate is increasing dramatically with
small valve stroke
Regards,
Ahmed Sabry
Control and Instrumentation Engineer
GPC - General Petroleum Company
CELL.: 00 2 0121367310
Is This Answer Correct ? | 2 Yes | 2 No |
Answer / manivannan
x-axis controller output;y-axis stem position graph is
linear curve
Is This Answer Correct ? | 1 Yes | 10 No |
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