Kapat KARAT-520, Operation Manual

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2. INTENDED USE
2.1. Operating limitations
In order to provide proper operation of flowmeters it is required to
obey the following limitations:
n
hydraulic strength, MPa……………...…………...................…...2,5;
n
excess pressure of working fluid on the output of a flowmeter:
ND 20, -25, -32, MPa, not less than ..........…………. 0,05
ND 40, -50, -65, -80, MPa, not less than ..……...............0,1
n
never place flowmeters nearby intense electromagnetic field
sources (power transformers, electric motors, frequency convert-
ers, unscreened power cables and so on);
n
never lift flowmeter by EM and install flowmeters on the EM side (fi-
gure 2.1);
n
never connect several flowmeters to one power supply unit;
n
never use flowmeter in the capacity of MI during site welding on sys-
tem pipelines.
Figure 2.1 – Unacceptable actions when working
with flowmeters
2.2. Recommendations for choosing a flowmeter
Choosing the optimal dimension type of a flowmeter is the main con-
dition of its reliable operation, durability and acquisition of consistent
measurement results.
The main selection criteria are the following:
n
technical specification compliance to design parameters of engi-
neering system (flow range, pressure drop in pipelines), where
a flowmeter is installed;
n
nominal pipeline diameter should correspond to flowmeter dimen-
sion type.
When choosing the flowmeter dimension type the following condi-
tions should be observed:
n
calculated operating flow rate of measured fluid in a pipeline should
be within the range of 0,25Q – Q for selected dimension type of
nom nom
a flowmeter (table 1.2 of the following manual);
It is recommended to choose a flowmeter with Q transition flow value
t
(table 1.2) less than minimum calculated flow value of measured fluid
in the pipeline for the purposes of commercial metering.
СМАФ.407251.002 РЭ – Operations manual Edition 3.0. August 2012
30
КАRАТ-520 Ultrasonic flowmeters
КАRАТ RPA www.karat-npo.ru