Flowmeter SVTU-11B, Operating Manual

Page: 26 / 68

26
WARNING!
Ultrasonic flow sensors contain piezoceramic elements and thin-walled design ele-
ments, which have the increased fragility and do not permit shock and excessive compress-
ing loads.
That is why
I T I S F O R B I D D E N :
−
to swap around flow sensors for different channels;
−
to install flow sensors with marks “11” (“21”), intended for installation in the first
flow meter bush (according to flow direction), into the second bush and sensors with marks
“12” (“22”) to install into the first bush;
−
to drop ultrasonic flow sensors or to knock on them at transportation and installation;
−
to carry out mounting and dismantling of FS with installed ultrasonic flow sensors;
−
to accomplish metalwork or welding works on the pipeline closely to FS with the in-
stalled ultrasonic flow sensors;
−
to exceed the mentioned above force for tightening of FlS;
−
to dismount stuck to FS flow sensors, while

turning them in bushes during regular
service.
9.4.2.3 For the removal of the flow sensor its design provides special elements.
The manufacturer has developed and can propose special removers or complete set of design
documentation for their manufacturing:
−
for FlS of DN 32…80 – see remover (SMP. 296454.004);
−
for FlS of DN DN 100…150 – see remover (SMP.296454.001).
9.4.3 Installation of temperature sensors
Temperature sensors (manufactured by SEMPAL Co.) RTD-T can be installed in two
ways:
−
by screw-driving in bushes (lugs) of the first type welded into the pipeline for direct
contact of the RTD with the water;
−
by screw-driving in thermal pockets, which, in turn, are screwed in bushes (lugs) of
the second type. The last ones are welded into the pipeline for contact with the water via a
protective thermal pocket.
Choosing a way of RTD installation in the pipeline it is necessary to consider, that to
obtain a maximal accuracy of temperature measurement the sensitive element of RTD
should be arranged as close as possible to an axis of the pipeline. There are three types of
RTD with length of 58, 80, 150 mm (type 4, 2, 3 correspondingly) and variants of their an-
gular installation in accordance with specified requirement irrespective of pipeline diameter.
The inclination angle and depth of RTD immersing is provided with use of bushes (lugs), the
design of which depends on pipeline DN. Recommended variants of RTD depending on FS
type are given in tables 9.2 and 9.3. Variants of RTD installation in thermal pockets and
without it are given in figures 9.7, 9.8.
Warning! Applying lugs with inclination 45 or 60 °, it is necessary to provide a contact
of water with the bottom part of RTD, where thermosensitive element is located.
The installation place for each RTD included in delivery set is given on the meter’s
scheme for installation (see the appendix B). The RTD which measures temperature of the
water should be installed close to FS. The distance between the RTD and the calculator
should not exceed 10 m.