Furnace draft transmitter range is -50 to +50 mmwc. why the
impulse line connected in hp side?
- 2 Answers
- 12582 Views
- Arena, I also Faced
- E-Mail Answers
Answer Posted / carl_ellis
A draft range measurement is typically a gauge pressure
measurement, referenced to atmosphere.
Draft range is very, very low pressure, so DP transmitters
are typically used because they're readily available in
a 'draft' range with the large diaphragms necessary for low
pressure measurements.
The high side is connected to the process with an impulse
tube. The low side is exposed to atmospheric pressure.
Good practice puts a filter, like a scintered pneumatics
filter on the low side, so that dirt doesn't fill the low
side cavity and air movement (wind, passing vehicles) is
buffered and damped to prevent the forces of air movement
on the low side from affecting the draft measurement.
If the impulse line were connected to the low side, the DP
would be negative, a DP subtracts the low side pressure
from the high side pressure (atmosphere minus some positive
pressure = negative pressure). Convention says that draft
range is positive so the impulse connection is to the high
side, to get a positive value.
Tell 'em Carl sent you.
| Is This Answer Correct ? | 12 Yes | 1 No |
Post New Answer View All Answers
what is the imbustion control loop
HOW TO SOLVE PROBLEM WITH ENRAF LEVEL TRANSMITTER 854 ATG THAT PASSWARD DO NOT Exist INTO TRANSMITTER TO ADJUST LEVEL WITH PORTABLE PET 847, WRITTEN WRONG PASSWORD , I AM SURE THAT DEFAULT PASSWARD (W2=ENRAF2) IS THIS TRANSMITTER NEED TO REPLACE SOFTWARE AND HOW?
List three types Level Gauges with their working principles
Which type of diaphragm use in costic line, dm water line, natural gas line, oil line?
can anyone tell me about the basic concepts to consider before to start a PLC panel wiring
the 3 most common transmitter protocol being in refinery or qatar gas and aramco.
please send me some question papers of HPCL aptitude test ?? please send it to bipinb.28@gmail.com ...
what is scale factor of proximitor & unit of the vibration.
need to calculate flow rate with the help of dp range and orifice bore dia and size. range is 0 to 400 inwc and orifice size is 12 inch 150 # rf and bore dia is 7.180 inch. need to calculation for flow rate
what are the steps I have to deal with?
What is the purpose of the analyzer in petrochemical plant?
selection criteria of control valve? and selection criteria of actuator explain in brief?
What is the function of solenoid valve in on/off & shutdown valve and why it is not used in control valve normally?
i hav applied for the post of engg. in iocl so please require the past test papers fro instrumentation engg please please help me and send me the papers or tell me the pattern and type of ques asked in examination......
May I have a brief note above the voltage barriers? Whats is the purpose? Please mail me if you've operational details, mail id: rajkumar.diice@gmail.com
