Flow calculation table
Flow calculation table
(OP)
I'm looking for a table or list of conversion factors to use to calculate natural gas flow from a Barton dp recorder. As I understand, you take the square root of static line pressure X differential flow (in inches of water), and then multiply by a conversion factor for the line diameter and orifice diameter. I commonly work with 2" and 3" gas injection lines. Can anyone help provide, or point me in the right direction?
Regards,
symon
Regards,
symon





RE: Flow calculation table
and maybe sell you a new plate down the road
RE: Flow calculation table
It's not the sq rt of the DP, it's the sq rt of the DP normalized to percentage.
And you need to know the flow rate at 100% of the DP, at the top of the chart scale, which I'll designate 'max flow'.
The DP is normalized to percent; 0-100% across the chart range.
The square root of the normalized percentage is the percentage of flow rate.
So, picking round numbers to make it quick and easy
sq rt 100% DP = sq rt 1.00 = 1.00 = 100% of max flow rate
sq rt 81% DP = sq rt 0.81 = 0.90 = 90% of max flow rate
sq rt 64% DP = sq rt 0.64 = 0.80 = 80% of max flow rate
sq rt 49% = sq rt 0.49 = 0.70 = 70% of max flow rate
You get the idea.
RE: Flow calculation table
Back when people used mylar sheets for overhead projector slide presentations, I knew a guy who used the mylar sheets to create a flow scale overlay for his recorders that were mechanically configured to record only linear DP charts, 0-100%.
He drafted square rooted flow scales (like below) where the graph grid lines are labeled with flow values on the major divisions onto a mylar sheet.
He would overlay the transparent mylar over the DP linear chart and read the trendline against the mylar flow grid lines.
The graph below is an image of true legacy, an antique Brown (now Honeywell) with square rooted flow chart scales