What is the Difference between E/P Positioner and I/P
positioner in a control valve? In which applications the
respective positioners are used in?
Answer Posted / william z butryn
An I/P convertor is a device that converts an electronic
input signal (typically 4-20 MA @ 24 VDC) to a pneumatic
output signal(usually 3-15 or 6-30 PSI) depending on the
control pressure required. The output must be calibrated to
provide the desired percentage of span as the input span.
The output of this convertor will do NOTHING until it is
connected to another device. The other device can be an
actuator, positioner or other device requiring a pneumatic
control signal.
If an actuator is used, the actuator can be connected to a
valve stem, a damper or a lever. The actuator can then be
used to set the position of the connected device by moving
a shaft up and down corresponding to the pressure applied
by the output of the I/P convertor. An E/P can be construed
to mean a device that converts a voltage or electronic
input signal to a pnematic output signal. A P/I convertor
does the reverse and converts a pneumatic input signal to
an electrical or electronic output signal.
An EPP as it really should be designated, is an electro-
pneumatic positioner (which can also be a smart positioner)
that can provide a position feedback to itself through the
use of a lever connected between the positioner and the
controlled device that will move proportionately up or down
with the shaft movement of the control valve, lever or
damper to which it is connected. When the position feedback
signal has reached the corresponding percentage of span of
travel, the output signal will be adjusted accordingly and
stabilized to maintains and hold the desired position of
the device.
| Is This Answer Correct ? | 46 Yes | 4 No |
Post New Answer View All Answers
Why upper weighing limit of electronics balance is 90% of the total weighing capacity?
how to connect transmitter measuring sulfur process? 1-by using long impulse line or 2- by using coated short impulse line
How to Calibrate Interface Level Troll in field
How can a d.p. Transmitter be calibrated?
how to calibrate 0- 150 psi presure gauge by dead weght tester
key phaser where is use and work
What are different types of orifice plates?
all questions related to instrument technician in any offshore oil and gas company.
What is limitation of the ht.of the displacer of a level trol?
Hi Friends , i need one urgent help , i am preparing for M.tech entrance examination , i need some obejective questions related to instrumentation field. where can i get those ? can anyone help me pls ?
in which principle pressure tx,level tx ,flow tx,temp tx ,control valve works?
any body who gone thru recent iocl interview.INSTRUMENTATION questions. I need.
Positioner usage.
all types instrumentation questions want
Define cryogenic?