ARI Armaturen PREDU 700 EN - Manual (Page 13)

Rev. 0040701000 1714 Page 2-13
Operating and installation instructions
PREDU
®
5.6 Strainer
5.7 Safety valves
6.0 Putting the valve into operation
-
ATTENTION !
Install a strainer before the pressure reducing valve, with the sieve sideways
(with the medium steam) to avid the collection of condensate.
The strainer must be cleaned from time to time.
-
ATTENTION !
The system part behind the pressure reducing valve (downstream pressure
side), the control line and actuator must be protected against excess pressure.
The necessary safety valve must be dimensioned so that by max. possible
upstream pressure, by fully open pressure reducing valve, the max. possible
capacity must be blown of by the safety valve.
The set pressure must be conform to the system part with the lowest nominal
pressure.
An adequate distance must exist between the set downstream pressure and the
safety valve set pressure.
If not secured that the bypass line works even more than the pressure reducing
valve or can be open parallel to it, the capacity rating for the safety valve must
include the extra capacity.
ATTENTION !
- Before putting the valve into operation, check material, pressure, temperature
and direction of flow.
- Regional safety instructions must be adhered to.
- Residues in piping and valves (dirt, weld beads, etc.) inevitably lead to leakage.
- Touching the valve when it is operating at high (> 50°C) or low (< 0°C) media
temperatures can cause injury.
Affix warning notice or protective insulation as appropriate!
- The water seal pot is available for media temperatures over 100 C (NBR-
diaphragm) or 130 C (EPDM-diaphragm).
- The water seal pot is completely filled (by steam with water) and the actuator is
bleeded by the plug (refer to Fig. 5).
Before putting a new plant into operation or restarting a plant after repairs or
modification, always make sure that:
- All works has been completed!
- The valve is in the correct position for its function.
- Safety devices have been attached.