Flomec Oval Gear, Руководство по эксплуатации

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10
2.1.4
Filtration / Straining
It is recommended to fit the inlet side of your flowmeter directly to a strainer of
appropriate pipe size and mesh size. The minimum mesh size as shown in the specifications
section of this manual should be adhered to where ever possible. When metering medium
or high viscosity fluids it may be necessary to use a strainer one pipe size larger than the
flowmeter nominal size, in order to limit the pressure drop across the strainer basket and
maintain strainer efficiency
(i.e. a 1.5” strainer on a 1” meter).
In systems where there is potential for hard particles of any size, the filtration levels of the
system should be improved so as to eliminate the flow of hard particles through the meter.
While soft particles may pass through the rotating meter components without damage (if
they are small enough) hard particles are abrasive and will always cause rotor and bearing
damage regardless of size.
2.1.5
Pipe Connections
When installing a flowmeter, it is important that no upstream pipe join between the
flowmeter and the strainer are sealed using PTFE sealing tape. Lose pieces of PTFE tape
are common causes of failure in new meter installations due to the tendency to wrap
around the rotating components inside the meter. It is recommended that the sealing of
pipe joins should be done with a sealing paste or liquid (such as Loctite® 565 thread
sealant paste).
Flanged connections should be made using gaskets and bolting suitable for the metered
liquid and the system pressure; flowmeters fitted with stainless steel flanges may be
installed using metallic gaskets and high strength bolting if required. For meters fitted
with Aluminium flanges it is only suitable to make pipe connections in accordance with
the relevant flange standard requirements for cast iron flanges; gaskets according to
ASME B16.5 Annex C gasket group 1a are recommended, and only low strength or
intermediate strength bolting may be used.
For all flanged pipe connections to flowmeters it is essential that flange faces are well
aligned and closely fitting.
Flange bolts in Aluminium flanges should never be tightened to torque
values greater than 110ft.lb (150Nm)
CAUTION