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5.
ASSEMBLY
During the assembly of balancing valves following rules should be observed:
-
to evaluate before an assembly if the valves were not damaged during the transport or storage,
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to make sure that applied valves are suitable for working conditions and medium used in the plant,
-
to take off dust caps if the valves are provided with them,
dust cap
-
to protect the valves during welding jobs against splinters and used plastics against excessive temperature,
-
steam pipelines should be fitted in such a way to avoid condensate collection; in order to avoid water hammer steam trap
should be applied
Pipeline where the valves are fitted should be conducted and assembled in such a way that the valve body is not
subjected to bending moment and stretching forces.
Bolted joints on the pipeline must not cause additional stress resulted from excessive tightening, and fastener
materials must comply with working conditions of the plant,
-
during pipeline painting valve stem should be protected,
-
stop valves can be assembled in any position, however it is recommended to install the valve with handwheel upwards,
-
screw down and non-return valves (version with spring) can be assembled in any position, screw down and non-return
valves (version without spring) should be assembled only on the horizontal pipelines with handwheel upwards
It should be take note of medium flow direction, marked with an arrow on the body. Flow direction is established
according to the rules as below:
Stop valve
SDNR
valve
and
throttling valve
Stop valve
PN6 – PN25
PN6 – PN40
PN40
under the disc
DN15 – DN150
DN15 – DN300
DN15 – DN100
on the disc
DN200 – DN300
-
DN125 – DN200
-
before plant startup, especially after repairs carried out, flash out the pipeline through entirely open valve, in order to
Flow on the
disc
Flow under the disc
