KROHNE Summit 8800 Vol 2 - Manual (Page 157)

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08/2013 - MA SUMMIT 8800 Vol2 R02 en
SUMMIT 8800 VALVES 11
11 .5 Four way
The four way valve, also known as a diverter valve, is often used to reverse a flow, but may be
used for other purposes also. The valve opens and closes two different pipes, but only one will
be opened and one will be closed at the same time.
Two signals are used to control the valve: forward and reverse which have digital status feed-
back signals.
The parameters needed are:
Figure 170 Four way valve configuration for different leak sensors types
Parameters:
Leak sensor
Source used to detect leaks:
- None No leak sensor used
- Status A digital status input is used to indicate if there is a leak
- Sensor A analog or Hart input is used to connect a sensor to measure the leak size.
Leak detect When to detect leaks
Open and close durations Length of time the corresponding command is sent
Transition duration Maximum time it should take for the valve tobmove. If time is exceeded
then an alarm will occur.
In case a sensor is used:
Leak sensor units
Units for the sensor
Sensor max and min The Highest and lowest value the sensor can give
Use leak sensor units In case of a Hart sensor: uses the sensor units instead of the earlier
entered units
Correct leak sensor units In case of a Hart sensor: uses the sensor units instead of the earlier
entered units
The actual control of the valve must also be defined (see also volume 3):
• As a fixed keypad value, entered above
• In the modbus list to remotely control the value
• On display to locally control the valve
And can be selected as follows: