Functions
Part 1 • Page 6-5
Part 1 – Operating Instructions
Rev. 6.4 dated 2022-02
Software Released Version: 1
(Eco)RO Dia II
Part 1 • Chapt
er 6
6.2.8
Ring piping pressure
The following factors determine the pressure ratios in ring piping:
•
The maximum consumption (number of dialysis stations and other consumers)
•
The minimum flow speed required (to avoid contamination)
•
The minimum supply pressure at the last tapping point
•
The pipe geometry (pipe cross-section etc.)
The overflow valve
ÜV1
at the end of the ring piping must be set according to customer requirements.
Without permeate discharge and maximum performance, the setting pressure via
ÜV1
should be
2.0 – 3.5 bar. The flow speed in the primary ring piping must reach 0.5 m/s (with full discharge).
6.2.9
Membrane pressure vessel in the ring piping
The required constant pressure and an adequate supply of permeate is ensured by installing a membrane
surge tank. In turn, the size of the tank and the necessary membrane air pressure depend on the factors
listed under
Part 1, chapter 6, paragraph 6.2.7 “System production pressure”.
B. Braun prescribes a weekly check of the Hydrowatch on the installed membrane surge tank (DG). If the
red indicator is visible in the viewing glass, please contact your B. Braun Avitum AG service technician
immediately.
6.2.10 Prevention of excess pressure in the ring piping
An increase in pressure after reverse osmosis may well be possible if a shutoff cock is blocking the ring
piping. The pressure switch
PSAH1
prevents the pressure increasing above the set value. After the
system has switched off, the corresponding message appears on the display
A faulty expansion membrane on the surge tank also leads to an increase in pressure when the system
is switched on, and thus to the system being switched off via pressure switch
PSAH1
(factory setting:
switch-off pressure = 6 bar / switch-on pressure = 4 bar).
6.2.11 Temperature-dependent discharge
6.2.11.1 Discharge through temperature discharge dialysis menu or standby mode (analogue value)
When an adjustable start temperature has been reached in the permeate (factory setting: start 35 °C / stop
33 °C), the system discharges the concentrate via
Y9
depending on
LSHL2
until the temperature drops to
below the stop value.
6.2.11.2 Discharge via alarm evaluation (digital signal)
When the limit temperature set on the temperature limit value controller has been reached, the system
discharges the concentrate via
Y9
depending on
LSHL2
until the temperature drops below the limit value.
The operating message “Alarm 21, temperature too high” appears on the display.
6.2.11.3 System stop via error evaluation (digital signal)
When the set limit temperature is exceeded for more than 3 minutes (alarm 21), the system switches off
(consumer protection).
IMPORTANT The Hydrowatch must be checked before and after each disinfection. If the red indicator is
visible, the ring piping must not be disinfected.