Yokogawa RotaMASS 3-Series - Manual (Page 59)

8. GENErAL SPECIFICATIONS
8-5 IM 01R04B05-00E-E 3rd edition July 30, 2010 -00 all Rights Reserved. Copyright © 2005, Rota Yokogawa
PrESSUrE LOSS
Pressure loss depends on velocity, viscosity and density of
the fluid. For newtonian fluids the pressure loss is shown in
table 8 (1 kg/l, 1 mPas).
table 8: Pressure loss
type RCCS30 RCCS31 RCCS32 RCCS33
Qmax bar 4.45 2.72 2.34 2.50
Qnom bar 1.11 0.97 1.00 1.01
type RCCx34 RCCx36 RCCx38 RCCx39
RCCx39
/IR
RCCx39
/XR
Qmax bar 2.50 3.01 3.58 2.35 1.40 1.42
Qnom bar 0.98 0.95 0.97 0.98 1.00 1.04
notE :
- For correct pressure loss determination please use the
Yokogawa sizing program.
- the pressure losses are valid for constant flows. Pulsating
flow causes a considerably higher pressure loss on average.
PLANNING ANd INSTALLATION HINTS
design Limits
It is the responsibility of the user to use the instrument with-
in the given design limits. Erosion and corrosion influence
the accuracy and may restrict the temperature / pressure
limits. therefore corrosion and erosion should be avoided.
Installation
the flowmeter can be installed vertically, horizontally or
in any other position, as long as the measuring tubes are
completely filled with the measured liquid during measure-
ment.
redundant installation
If two flowmeters of the same size are installed in series
mutual interference called cross talk may take place. Cross
talk occurs due to the fact that both meters have the same
resonance frequency. If serial installation is planned please
contact your Yokogawa representative who can ensure that
a frequency adjustment is made to one of the meters at the
factory.
Sizing
the measuring range and accuracy are virtually indepen-
dent of fluid conditions and size of the connecting pipe. Se-
lect a suitable nominal size from pressure loss calculation.
Check whether the measuring range and accuracy at mini-
mal flow fit the application. the calculations of the pressure
loss are based on newtonian fluids. For correct calculation
of the pressure drop use the RotaMaSS Sizing software
DuREP V which is part of the Yokogawa Flow Configurator.
Sanitary Applications
For sanitary applications select process connection S2, S4
or S8. the wetted surface will be Ra ≤ 1.6µm. However, if
option /SFx is selected the surface roughness will be
Ra < 0.8µm and with /SF2 a certificate with a 3- point
roughness measurement is delivered. the EHEDG certificate
shows that RotaMaSS conforms to the EHEDG criteria
regarding the capability to be cleaned by a CIP process.
the evaluation does not include the process connections
and seals.
Cavitation
to avoid cavitation keep the back pressure of the fluid
sufficiently above the vapor pressure of the fluid. For low
viscous fluids following condition should be fulfilled at the
given temperature:
p
back
> p
vapor
+ 0.7*∆p
With ∆p = pressure loss (e.g. given by the sizing program)
Long Term Stability
to get stable deflection of the tubes by the coriolis forces
the stiffness and therefore the wall thickness has to kept
constant during measuring. With corrosion or erosion the
meter factor is drifting with time and recalibration is necessary.
Select the suitable resistant tube material for the process!
recalibration Service
Yokogawa offers via its European Flow Centre (Rota Yokogawa,
Germany) full recalibration service, if necessary with a
certificate traceable to German national standards. Please
contact your Yokogawa affiliate or directly Rota Yokogawa,
Germany.
Heat tracing and insulation
Basically the detector can be insulated by the customer.
the converter should not be exceeded more than 50°C.
therefore never insulate the converter and keep the neck
free from insulation too. to be sure not to overheat the
connection box choose one of /tx options (insulation or
heat tracing from Yokogawa). For temperatures between
150°C and 230°C choose /Mt option and remote installa-
tion. For low temperature fluids ask for special insulation.
Installation above 100°C process temperature
to provide enough cooling the instrument should be
installed vertically or horizontally with the converter down.
this is recommended for size RCCt/S36 and larger without
/tx option.
Installation below 0°C process temperature
the detector can be insulated to prevent ice capping either
by the customer or by the manufacturer. ask your Yok-
ogawa representative for special insulation. If the customer
wants to insulate by themselves a closed cell foam as in-
sulation material is recommended to avoid water siphon. In
this case option /S2 should be selected. For temperatures
below -70°C option /Lt is recommended (on request).
Zero adjustment function
Zero point can be adjusted either by setting the switches
on display or with the HaRt communication or with status
input when the fluid is stopped and the detector filled. to
ensure no flow conditions isolation valves should be in-
stalled. to achieve the specified accuracy a zero should be
performed at process conditions (temp., pressure).
Pressure / Temperature dependencies of process connec-
tions
See also process pressure limits in chapter ”normal opera-
tion conditions”.