VortexMaster FSV430, FSV450 SwirlMaster FSS430, FSS450 | CI/FSV/FSS/430/450-EN  Rev. G  21 
 
 
Fig. 8:  Pipe sections with pipe elbows 
 
Installation  Inlet section  Outlet section 
Single pipe elbow 
upstream or 
downstream of the 
meter tube 
min. 3 x DN  min. 1 x DN 
 
If the elbow radius of single or double pipe elbows positioned 
upstream or downstream of the device is greater than 
1.8 x DN, inlet and outlet sections are not required. 
 
VortexMaster FSV430, FSV450 
In order to maximize operational reliability, the flow profile at 
the inflow end must not be distorted if at all possible. 
The figures below show the recommended inlet and outlet 
sections for various installations. 
 
 
Fig. 9:  Straight pipe sections 
 
Installation  Inlet section  Outlet section 
 Straight pipe  min. 15 x DN  min. 5 x DN 
B Valve upstream of 
the meter tube 
min. 50 x DN  min. 5 x DN 
 Pipe reduction  min. 15 x DN  min. 5 x DN 
 Pipe extension  min. 18 x DN  min. 5 x DN 
 
 
Fig. 10:  Pipe sections with pipe elbows 
 
Installation  Inlet section  Outlet section 
 Single pipe elbow  min. 20 x DN  min. 5 x DN 
B S-shaped pipe 
elbow 
min. 25 x DN  min. 5 x DN 
C Three-dimensional 
pipe elbow 
min. 40 x DN  min. 5 x DN 
 
5.1.3  Avoiding cavitation 
To avoid cavitation, a static overpressure is required 
downstream of the flowmeter (downstream pressure). This can 
be estimated using the following formula: 
 
ppp
 6,23,1
21
ρ
1 
ρ
2 
ρ' 
Static gauge pressure downstream of the device (mbar) 
Steam pressure of fluid at operating temperature (mbar) 
Pressure drop, measuring medium (mbar) 
 
5.1.4  Installation at high measuring medium temperatures 
 
Fig. 11:  Installation at high measuring medium temperatures  
 
At high measuring medium temperatures > 150 °C (> 302 °F), 
the sensor must be installed so that the transmitter is pointing 
to the side or downward. 
 
G11752
≥3 x DN
≥1 x DN
≥1,8 x DN
G11751
≥15 x DN ≥ 5 x DN ≥50 x DN ≥ 5 x DN
≥15 x DN ≥ 5 x DN ≥18 x DN ≥ 5 x DN
A
B
CD
G11752
≥ 20 x DN ≥ 5 x DN
A
B
≥ 25 x DN ≥ 5 x DN
C
≥ 40 x DN ≥ 5 x DN
G11755