6 Commissioning/Start-up/Shutdown
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0570.81/22-EN
6.3 Shutdown
6.3.1 Measures to be taken for shutdown
During prolonged shutdown periods, ensure that the following conditions are met:
1. Drain fluids which change their physical condition due to changes in
concentration, polymerisation, crystallisation, solidification, etc. from the piping.
2. If required, flush the piping with the valves fully opened.
6.3.2 Servicing/Maintenance
The valve has been designed to be largely maintenance-free. The materials of the
sliding parts have been selected for minimum wear.
NOTE
If several valves are serviced at the same time, take appropriate measures to
prevent the dismantled parts from getting mixed up.
The service life can be extended by taking the following measures:
▪
Checking the function by opening and closing the valve at least twice a year
▪
Lubricating the moving parts such as stem 200 and gland bolts (not for oxygen
valves) using appropriate lubricants (e.g. lubricants suitable for high
temperatures)
▪
Adding or replacing packing rings in gland packing 461 in time
▪
Re-tightening or replacing the bonnet/cover gasket 411.1 in time
Testing overhauled valves
After reassembly and prior to commissioning/start-up, the valves must be subjected
to shell testing and leak testing to DIN EN 12266-1.
Body pressure relief valve
DANGER
Gate valve is not closed.
High-pressure hazard!
Leakage of hot and/or toxic fluids!
Risk of burns!
▷
Close the gate valve.
▷
Perform work with utmost care, making sure that all safety measures are
complied with.
Leakages at the seat caused by foreign objects between the body seat and valve disc
can be removed by briefly lifting rod 574 and allowing valve disc 350 to snap back
onto the seat. This is done by inserting two screw drivers on opposite sides into the
rod's groove.
If leakage cannot be eliminated, this indicates that the seating faces are damaged. If
this is the case, the body pressure relief valve needs to be replaced the next time that
the system is shut down.
CAUTION
Bursting discs are not marked
Risk of mixing up bursting discs!
▷
Always select the bursting disc according to the name plate in its packaging.
▷
Do not mix up bursting discs.
