Product Overview
.03
.06
Δ
p
G
(l/s) (
gpm
)
0.1
1
0.2
0.3
0.5
(psi) (bar )
10
2
3
5
20
0.01
0.1
0.02
0.03
0.05
1.0
0.2
0.3
0.5
0.4
4
0.04
0.4
.30
.50
1.4
2.8
5.6
1
0.2
0.5
2
5
10
2
0
5
0
100
2
00
.015
46.00
20.00
10.00
9.00
7.00
5.00
2.00
1.50
1.00
0.70
0.50
0.20
(feet of head)
0.05
3.00
0.30
0.11
0.003
0.005
7.0
12.5
.02
0.3
.10
.20
.70
3.0 gpm
2 3
Position
1
2.5 0.5 1 .5 3.5 4
Cv
Max
Size 3/4"
0.5 1 1.5 2 2.5 3 3.5
Cv 0.55 0.8 1.2 1.7 2.4 3.7 4.4 5.0
Position
4
Code 142251A 3/4”
Benefit
For a given flow rate and valve size, the variable orifice type design results in a greater differential pressure signal than fixed orifice designs. In
very low flow applications, the differential pressure value from a fixed orifice design can be small in relation to the accuracy tolerance of the
measuring instrument. As a result, for such applications, the variable orifice design, which delivers a higher value in relation to measurement
accuracy tolerance, can result in more precise balancing.
Effect of fluid conditions
To ensure accurate pressure measurement, care should be taken to ensure fluid is of high quality and absent of particles. Fluid impurities can cause erratic
pressure signal readings, especially at very low flow rates or when the valve is closed more than 75% of full open. In hydronic applications, it is advised to
use a dirt strainer, filter or separation device to protect against particles and debris.