TapFlo Guardian system Mk3.1, Operation & Maintenance Manual, Page: 12 / 44

BARRIER & STOP (BARR)
Issue : 020913-B TPUK-GU31X 10
Principle of operation
Barrier or containment AODD pumps typically contain an additional set of
diaphragms used to back-up the primary diaphragms.
In the event of a breach in the primary diaphragms the back up diaphragms
prevent the pumped media from being spilled from the exhaust of the AODD
pump (typical failure), which could pose significant risk to plant and personnel
near by.
Typically no additional system is used to determine if a breach has occurred
and the fault goes unnoticed, contaminating the media with incompatible
materials, and eventually the back up diaphragms breach and a spill occurs,
defeating the principle of the pump.
The Guardian monitors the pressure in the voids between the primary and
back up diaphragms of the AODD pump, stopping the AODD pump if the
pressure in the voids increases above the set point, preventing the spill and
containing the leak in it’s media compatible chamber.
Fig. BARR-01 shows a graph of time against pressure showing barrier breach
and stop principal
Fig. BARR-01