Differential Pressure Created by Orifice

The differential pressure across an orifice is proportional to the square of the velocity.

To answer your questions,

1) Yes, if you can tolerate the higher velocity and differential pressure.

2) It is the varying flow rate (velocity) that creates the varying differential pressure.

thank you sir for your prompt reply. I have one more query for point number 2. During sizing i came to know for the same flo suppose for 100 m3/hr i can select different different Differential Pressure i.e. By keeping my velocity constant how can i create different DP.

1) Yes, the same orifice can be used if it will withstand the deflection forces from the increase in line pressure needed to double the flow rate.

2) The Beta ratio is the ratio of the orifice bore diameter to the ID of the pipe. If you use the same orifice plate, it must have the same Beta ratio: same orifice bore, same pipe ID.

When the flow doubles, and the bore diameter stays the same, the DP goes up by a factor of 4 to 10,000mm H2O by the Swiss guy Bernoulli's principle.

The orifice sized for 100m3/hr can be used for 200m3/hr. The differential pressure will be Higher (i.e) four times of original differential pressure. Correspondingly the pressure loss in the orifice (irrecoverable pressure) will increase. Hence if process can accept the increased pressure loss, the same orifice can be used. However the dP transmitter to be recalibrated to the increased differential pressure.

R.Thiyagarajan

your senior is correct, orifice can be use but this will be increase of uncertainty of orifice

please simulated new data in your software