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Specifications subject without notice
Edition: August 2017
Operating instructions BA 14b-02_EN
Danger
The valve should only be operated and serviced by personnel appropriately qualified for pressurized
pipelines:
Skilled staff in the sense of these operating instructions is persons who, as a result of their training, their knowledge
and their experience, as well as their knowledge of the relevant standards, are able to judge the tasks assigned to
them and are able to recognize possible dangers.
Make sure that the pipeline and control equipment have been installed correctly and are checked at regular intervals. The
valve body wall thickness must be designed to take into account an additional load Fz in the usual order
(Fz = π/4•DN²•PS) for a correctly sized pipeline.
The valve needs to be connected correctly to the pipeline and to the control equipment.
Make sure the usual flow velocities are not exceeded in continuous service in this pipeline. Exceptional operating
conditions such as oscillations, water hammering, cavitation and large proportions of solid matter in the process medium,
especially abrasive, must be clarified beforehand with the manufacturer.
That operating parameter near the cavitation limit and/or sound emission clearly above 85 dB, have been approved with
the manufacturer Pfeiffer.
Warning
We recommend to
open
and
close
the valve regularly. Depending on the valve model, we recommend opening
and closing the valve at least once a year.
Depending on how long the valve remains in one position, breakaway and operating torques may differ
considerably than those specified in the data sheet.
Attention
For double eccentric valves:
Make sure, that the butterfly disc is always operated within a range of between 0° - 90°. Turning the butterfly valve
over 0° leads to irreparable damage to the sealing ring e.g. sealing strip, this must therefore be avoided.
Butterfly valves that are operated at temperatures greater than +50°C or lower than -20°C must be protected, together with
the pipeline connections, against being touched.
2.3
Particular hazards
Danger
Prior to unscrewing the bonnet or removing the butterfly valve from the pipeline,
relieve pressure entirely in the
pipeline
to ensure the process medium cannot escape uncontrollably from the pipeline.
Warning
Should it be necessary to remove a butterfly valve from the pipeline, process medium may escape from the pipe
or out of the butterfly valve. In the case of process media that can damage health or are dangerous, drain the
pipeline completely before removing the butterfly valve from the pipeline.
Take special care concerning any
remaining media that may still be in the pipeline or have collected in the
cavities of the valve
.
Warning
For butterfly valves intended for dead-end service:
During standard operation, in particular, with gases or hot and/or dangerous
media, mount a blank flange at the free end connection or ensure that the
butterfly valve is properly protected against unauthorized operation.
Warning
If a butterfly valve used for dead-end service must be opened in a pressurized
pipeline, special care must be taken to ensure that any process media
escaping under pressure do not cause any damage.
Note
Application as end valve:
The valve must be mounted, so that the fastening ring mounted on the valve
body with cheese screws i.e. tension spring, is pressed against the piping
flange.
Sealing cannot be guaranteed, if mounted in reverse.
Danger
For Butterfly valves with adjustable Stuffing box:
The shaft is sealed with a stuffing box packing. Prior to unscrewing the stuffing box gland, relieve pressure entirely
in the pipeline to ensure the process medium cannot escape uncontrollably from the stuffing box packing.
