Liquid Controls Gear Plate Selection Guide - Manual (Page 7)

7
Examples
Formulas for Computing Gear Plate Ratios
Example 1: Find a gear plate ratio for 7.50 pounds per
gallon.
Meter Model: ------------- M7-A
Unit of Measure: -------- pounds per gallon
Packing Gland Ratio: -- 2:1
Units per Gallons: ------ 7.50
Adjuster Ratio: ---------- 3.997
Nb x Rc Dn
Pg x W x Ra Dr
= R1 R2 =
5.555 x 10
2 x 7.50 x 3.997
= R1 = .9265
61 57
Dn
Dr
Dn 57
Dr
61
R2 = = = .9344
∆R =
= = .85%
100 (R1-R2)
R1
100 (.9265 - .9344)
.9265
Example 2: Find a gear plate ratio for Imperial Gallons
at 2% correction.
Meter Model: ------------- M7-A
Unit of Measure: -------- whole imperial gallons
Correction Factor ------- (2%) .98
Packing Gland Ratio: -- 2:1
Units per Gallons: ------ .83267 Imperial Gallons per US
Gallon
Adjuster Ratio: ---------- 3.997
Nb x Rc x .98 Dn
Pg x W x Ra Dr
= R1 R2 =
5.555 x 10 x .98
2 x .83267 x 3.997
= R1 = 8.1785
Dn Dn Dn
Dr Dr Dr
R2 = x x
60 67 75
30 41 30
R2 = x x = 8.1707
∆R =
= = .095%
100 (R1-R2)
R1
100 (8.1785-8.1707)
8.1785
Dn Dr
41 67
Dn Dr
30 60
Dn Dr
30 75