Flowserve Selfacting pressure regulator - Manual (Page 19)

19
Contact the manufacturer if the prevailing installation conditions mean that the
valve will have to be fitted horizontally.
• Is there a suitable surge section upstream and downstream
of where the valve is installed?
The absence of a surge section can create critical operating conditions and
cause impermissible levels of noise and vibration!
• Is appropriate equipotential bonding provided?
Impermissible electrical compensating currents across the valve and the actuator
can generate static and cause electrical discharging.
In explosive atmospheres, the only valves that may be used are
those that comply with the permitted group, equipment category
and temperature class requirements laid down in Directive 94/9/
EC (ATEX)!
Recommended installation
Successful use of the automatic regulator is conditional
on the availability of a suitable installation environment.
We suggest that the recommended values be adhered to, as it is very important to take
account of physical aspects when using the regulator. Deviations can result in significant
control deviations, and in the worst case expensive rerouting of the piping will be necessary.
However, some physical processes will permit a deviation from these values, although in such
cases system knowledge is required, as is the express approval of the manufacturer.
Physical requirements
• Automatic regulators of this type are primarily used for water vapour,
vapours and gases. Under certain circumstances they can be used
with neutral liquids, although the plug inflow is in the closing direction
and “hammer” may occur near the closing point at levels below about
20 %.
• Realistic control ratio 1:10
• A water rundown tank will be required at temperatures above 100 °C
to prevent the membrane from overheating!
• To keep friction losses, wear, hydraulic shock and flow noise to
acceptable levels, the exit velocities for
vapours and gases of 70 m/s, and
liquids and saturated steam of 8 m/s
must not be exceeded.
EN