Scraper pig detection
Note
Not for critical operations
The "Scraper pig detection" function is not infallible. There are occasions where the system
may not detect the scraper pig. This function should be used for reference only and not relied
upon for critical operations.
● The scraper pig detection is derived by the loss of signal caused by the passing of scraper
pigs. Certain scraper pig designs may not have sufficient mass, or center core, to block the
signal resulting in a missed detection. Typically this can happen with inspection pigs.
● The maximum length in the scraper pig detection settings has to consider the total length of
the scraper pig, plus the expected waste buildup moving in front of the scraper pig.
Typical causes of air in the liquid
● The pump cavitates, the rotary speed of the pump is too high in relation to the supply of liquid
to the pump.
● The flow rate in the pipe is too high, so components installed upstream of the flowmeter can
cause cavitation.
● If there is a filter installed upstream of the flowmeter, it may be close to blocking, which also
can cause cavitation.
● Liquid flashes to vapor bubbles while passing through partially open valves or orifices.
9.7 Device status icons
Messages are shown in the display.
● In the operation view the alarms are shown as a combination of symbol and text in the lower
line of the display. If several diagnostic messages are active at the same time, the most
critical is shown.
● In the alarm list view all active alarms are shown as a list. The alarm list combines a symbol,
text and an alarm ID number. The alarms are arranged according to the alarm ID numbers.
The alarm list view can also be accessed via Active diagnostic events.
● In the alarm history view the most recent alarms (up to 100) are listed. The alarm history log
can be viewed in Diagnostic log. The alarm history log can be reset in Reset log.
Characteristics of messages
The device provides two types of alarm formats, Siemens standard alarm classes and NAMUR
status signals, selected in Status icons.
The following tables summarize the two types of alarm formats in an overview.
The sequence of the symbols corresponds to the priority of the messages, beginning with the
most critical.
Diagnostics and troubleshooting
9.7 Device status icons
SITRANS FST030 (Modbus)
100 Operating Instructions, 08/2018, A5E37367739-AD
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