10
1.3 Straight inlet
ULTRAFLOW® 54 requires neither straight inlet nor outlet in order to fulfil the
Measuring Instruments Directive (MID) 2004/22/ EC and EN 1434:2007. A straight
inlet section will only be necessary in case of heavy flow disturbances before the
sensor. We recommend to follow the guidelines of CEN CR 13582.
Optimal position can be obtained by taking the below-mentioned installation
methods into consideration:
Figure 9
A
Recommended flow sensor position.
B
Recommended flow sensor position.
C
Unacceptable position due to risk of
air build-up
D
Acceptable in closed systems.
Unacceptable position in open
systems due to risk of air build-up in
system
E
A flow sensor ought not to be placed
immediately after a valve, with the
exception of block valves (ball valve
type) which must be fully open when
not used for blocking.
F
A flow sensor must never be plac-ed
on the inlet side of a pump
G
A flow sensor ought not to be placed
after a double bend in two levels.
For general information concerning installation see CEN report
DS/CEN/CR 13582,
Heat meter installation. Instructions in selection, installation and use of heat
meters.
1.4 Operating pressure
In order to prevent cavitation the back pressure at ULTRAFLOW® 54 must be min.
1.5 bar at q
p
and min. 2.5 bar at q
s
. This applies to temperatures up to approx.
80
o
C.
