Fresenius Medical Care AquaA, Instructions For Use Manual

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Chapter 7: Functional description
Fresenius Medical Care AquaA IFU-EN-US 06B-2021 139
7 Functional description
This chapter provides a brief functional description of the AquaA
reverse osmosis system.
7.1 Description of the procedure
7.1.1 Functions
The AquaA is an industrial PC-controlled, fully automated reverse
osmosis system which uses pretreated soft water for the production of
highly deionized water, also called dialysis water.
The device consists of a water inlet section where the inflowing volume
of water is volumetrically measured and controlled in relation to the flow
(controlled shut-off).
The water is stored in a break tank and supplied to the pumps to
generate high pressure. Two pumps which are connected in series,
generate the high pressure and transport the water to the semi-
permeable membranes.
From the membranes, the dialysis water flows upwards to the dialysis
water outlet via the dialysis water collector, passing through pressure,
temperature and conductivity measurement along the way.
If the conductivity values exceed the programmed required value for
maximum conductivity, the dialysis water is returned to the break tank
via a bypass (on the
AquaA or RingBase ). To maintain the
programmed yield and the necessary diversion to drain, a small high-
pressure pump ensures circulation of the concentrate by bypassing the
membranes. This ensures silent, highly effective and economical
operation.
The concentrate to be discarded flows via a motor-controlled restrictor
to the drain.
7.1.2 RingBase
The dialysis water can be discarded via the RingBase before it enters
the ring main. This is particularly important during the start phase after
the system has been out of use for a longer period of time, in order to
prevent dialysis water with higher conductivity from entering the ring
main. The water from the ring return can also be directed directly into
the drain.