Answer / malaini

Manivannan answer is Linear curve. For equal percentage
every equal control valve opening will give equal
percentage incremental of flow rate. Tq

Answer / shyam

Through control valve flow characteristic ( cv )
we calculate flow rate at inlet & outlet pressure of
control valve.

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.

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

Answer / manivannan

x-axis controller output;y-axis stem position graph is
linear curve

For what reason would you possibly be compelled to make use of a Smith Predictor. Explain the idea behind the operation of this device.

0 Answers  

---

a pressure transmitter with a range of 0 to 2500kpag has a specified accuracy of 0.5 % of span.It is to be calibrated using a comparison gauge to have an accuracy of 0.1% of span.The comparison gauge has a range of 0 to 3000kpag What is the accuracy ratio? is this ratio acceptable?

1 Answers  

---

d/p flow transmitter LP side give to pressure.what you geting out put ? how you get(ma)?

6 Answers   ABB,

---

Turbidity analyzer working principle ?

0 Answers   Tata Steel Limited,

---

Why ues 250 ohms Resistor during hart type instruments calibration with hart protocol in details ?

5 Answers  

---

---

the whole paper was based on Transducers..questions like define repeatability, error,accuracy,precision..den there were many q. on the conversion of Pa to mmHg and other units.. also..der wer few Q. on some level sensors(with diagram)

0 Answers   GNFC,

---

HOW TO CHOOSE FREAQUENCY IN FMCW TYPE RADAR INSTRUMENTS. DESIGN BASIS OR DESIGN CALCULATONS ?

0 Answers   Chevron,

---

how to know the URL and LRL for steam drum level and why the calibration range is in negative ?

1 Answers   JSW, Samsung,

---

What are the difference between mass flow meter, magnetic flow meter and vortex flow meter.

1 Answers  

---

what is electric motorised valve working principle.

1 Answers  

---

How to calculate the Range of level transmitter ?

1 Answers   CPCL, Sejong, SSPL,

---

What are the two states of a controller

3 Answers  

---