Interested to Buy Any Domain ? << Click Here >> for more details...
How to Calibrate variable Head flowmeter (Orifice), here we
dont know High pressure and low pressure then how to apply
pressure on HP and LP side ?
- 1 Answers
- 5022 Views
- Nirma, I also Faced
- E-Mail Answers
Answer Posted / carl_ellis
The situation must be an installed, running system, with a receiver that displays a flow rate from the DP pressure signal, because no one just has a DP transmitter across an orifice plate for fun.
Every differential pressure primary flow element is assumed to be zero flow at zero DP. So the DP low side pressure 'zero' will always be zero DP, or when the 3 valve manifold has its process connection valves closed and the equalizing valve open.
The measured DP represents some flow rate on the square rooted curve of the normalized percentage of span.
In order to determine the DP span value, you measure the actual DP and note what the flow rate reads on the receiver (PLC/DCS/recorder/indicator/controller) at that DP.
Then you can calculate what the DP span value is for the max flow rate that receiver is configured for.
The receiver has some configured flow range: 0-500gpm? 0-1,000 bpd? 0-650pm? Find out what it is.
For example, say you measure a DP value of 700mm wc and that 700 mm wc shows a flow rate reading of 264.5 lpm on the receiver.
You have discovered that the receiver is scaled 0-500 lpm for that DP transmitter and the receiver does the square root extraction.
What is the flow rate as percentage of flow span?
264.5 lpm/500 lpm = 52.9% of flow rate span
52.9% normalized is 0.529
Since the flow rate is the square root of the normalized DP span, you need to square the normalized percentage of flow rate to find the equivalent percentage of DP span.
0.529^2 = 0.2798, or 27.98% (~ 28%) of the DP span.
If 700mm is 28% of span, 100% of span is 2500mm wc.
So the DP span for the transmitter is 0 (no flow) to 2500mm wc (max flow).
Carl Ellis
Measure First
| Is This Answer Correct ? | 0 Yes | 1 No |
Post New Answer View All Answers
What is zero elevation and zero suppression?
Coal mill Instruments Equipments for cement plant And process diagram ?
What is the purpose of LO Overhead tank in turbines.
NPN transistor, SCR, Zener diode, LED, Varactor diode, Vortex meter, RTD, Resistor, Crystal
hey any one got the papers of SAIL and HPCL plz do help me by posting them to my mail ID's naren07_87@yaho.co.in, surenarendra@gmail.com
How can we use feedback signal frm rtd for monitoring and in dcs for controlling ,then which type of rtd is sutaible 2 , 3,4wire and why ?
Specify eight technical requirements that you would consider important, when deciding upon a particular control valve?
what is actual drum level and compensated drum level?
Calibration procedure for water rotameters
How the sizing of the analog signal cable is calculate?
How to calculate mmwc values into tonnes?
Name different parts of a pressure gauge. Explain the use of hair spring in the pressure gauge.
Where are oxygen analysers installed in cfbc boilers? What are their usual readings?
full process of gas turbin?
how to tune siemens sipart electro pneumatic positioner..plz tel me..
