- To maintain the flow regime and satisfy the process design
characteristics.
- To positively isolate piping systems under pressure and certain items of
equipment.
- To allow harmless trapped gases to be vented, that might expand in the
valves cavity and effect the sealing characteristics of the valve.
- EB valves are used in cryogenic service to allow a rise in temperature
between centreline surface conditions and the operating handwheel. A
standard valve could be used, however it would require personnel protection
on the hands of the operator.
- Solid wedge gates in high temperature/high pressure should be avoided,
because of the expansion and the rigidity of the design will meen that
jamming/galling in the seat, when in the closed position, will become a high
probability.
- From the same manufacturer a welded bellow seal valve will be of a higher
integrity than a standard bolted bonnent valve for HP and HHP steam.
7.A no
Received on Mon Oct 08 06:15:00 2001
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