● Piping for Avoiding Bubbles
Flows containing both gas and liquid may not satisfy
the accuracy specifications of the instrument.
Prevent gas bubbles from forming in a liquid flow.
Piping should be carried out to prevent the build-
up of gas bubbles in the vortex flowmeter. Also,
install the valve on the downstream side of the
vortex flowmeter because pressure drop across the
control valve may cause gas to liquefy.
F0304.ai
Flow
Flow
Flow
(Good)
(Good)
(No Good)
Value
(No Good)
(3) Multi-Phase Flow
The vortex flowmeter can measure gas, liquid and
steam within the same structure. However, accurate
measurement of mixed flows (e.g. gas and liquid) is
not possible.
Mist flow
Stratified flow
Bubble flow
(No Good)
(No Good)
(No Good)
gas
liquid
F0305.ai
(4) Diameter of Adjacent Pipes and
Concentricity of Inner Diameters in Vortex
Flowmeter
Use the adjacent pipes which have a larger inner
diameter than that of the vortex flowmeter. Refer to
the table below.
Model code
Type of body
Adjacent pipe
VY015 to VY050 -0: General type Sch40 or pipe with
larger inner diameter
than Sch40
VY025 to VY080
-1: Reduced
bore type (1 size
reduction)
VY040 to VY100
-2: Reduced
bore type (2 size
reduction)
VY080 to VY400 -0: General type Sch80 pipe with larger
inner diameter than
Sch80
VY100 to VY200
-1: Reduced
bore type (1 size
reduction)
VY150 to VY200
-2: Reduced
bore type (2 size
reduction)
VY025 to VY150
-4: High pressure
reduced bore
type (1 size
reduction)
Sch160pipe with larger
inner diameter than
Sch160
• Ensure that the piping and pipe of the vortex
flowmeter are concentric.
• Ensure that the gaskets of adjacent pipes do
not protrude into the piping line.
F0306.ai
(No Good)
(Good)
D
1
D
1
< D
2
D
1
≥
D
2
D
2
D
1
D
2
(5) Other
The degree of protection of the vortex flowmeter is
of IP66/IP67 (JIS C 0920, IEC60629) or Type 4X
(NEMA250). Therefore, it cannot be used under
water.
<3. Installation>
15
IM 01F07A01-01EN
Installation
3
