Rerange orifice meters
Rerange orifice meters
(OP)
Hi everybody,
I have a question regarding orifice transmitter ranges. If you have a maximum dP range of 0-250 in H2O is there a common practice to design the plate so that the range is only 100 in H2O? In other words, would it affect accuracy if you instead range it for 175, 200, or even the 250 in H2O?
I need to re range current orifice meters and I need to increase the flow and I was wondering if there is a recommended maximum dP that we should design for. Thanks!
I have a question regarding orifice transmitter ranges. If you have a maximum dP range of 0-250 in H2O is there a common practice to design the plate so that the range is only 100 in H2O? In other words, would it affect accuracy if you instead range it for 175, 200, or even the 250 in H2O?
I need to re range current orifice meters and I need to increase the flow and I was wondering if there is a recommended maximum dP that we should design for. Thanks!





RE: Rerange orifice meters
Lately the DP Transmitters rangability is increasing, when the accuracy is getting better: Normal accuracy is at the 0.075% with 1:40 rangability (Rosemount, SMAR, Yokogawa, etc). I do not think there is a problem with changing the transmitter range, just make sure:
1. Readings are inside the transmitter range
2. Flow is not chocked at the orifice.
3. There are 7-10 x pipe Diameter length of stright pipe before the Orifice and 3-5 after it.
Cheers
RE: Rerange orifice meters
m777182
RE: Rerange orifice meters
RE: Rerange orifice meters
This is interactive with the flow element. Avoid a beta ratio, orifice plate bore/pipe id exceeding 0.7.
John