Danfoss MPE 70 Operating Manual page 8

Operating guide | MPE 70
8
3.2 Intended use
The MPE 70 is designed for use as energy
recovery device in Sea Water Reverse
Osmosis (SWRO) or Brackish Water Reverse
Osmosis (BWRO) system.
The MPE 70 must not be used for other
purposes than recommended and quoted
for without consulting your local MPE 70
distributor.
3.3 Application range
For application range see data sheet
"MPE 70 Pressure exchanger" available in ap-
pendix 11.1.
Applications not suitable for the MPE
70 can cause damages to the
MPE 70 unit, with risk of personal
injury.
3.4 Preferred system design
Danfoss recommends building systems with
a high degree of safety. Our preferred
system design can be found in the data
sheet "MPE 70 Pressure exchanger" in ap-
pendix 11.1.
• It is always the system builders' re-
sponsibility to ensure that the system
design does not cause any form of
hazard and are adapted to local regu-
lations.
• Proper installation and care of
shutdown devices and over-pressure
protection equipment is essential.
3.5 Initial start-up and settings of safety
equipment
The system designer is responsible to
design the equipment according to the
local regulations where the equipment
is running. According to PED 2014/68/
EU a risk assessment must be made to
identify and evaluate hazards which
apply to his equipment on account of
pressure.
Where under reasonable foreseeable
conditions, the allowable limits could
be exceeded, the pressure equipment
must be fitted with, or provision made
for fitting of a suitable protective
device.
180R9426 | AQ367027814446en-000801 | IOM MPE 70 | 08.2022
If positive displacement pumps are
used be aware they can build up
pressure exceeding the mechanical
strength of the membrane vessels,
pipes and other accessories. The pres-
sure rise can be fast and may exceed
the response time for electrical safety
equipment, like pressure switch and
control loop.
To prevent such over-pressurisation,
appropriate relief valves should be
used or procedures should be
implemented to safeguard the HP
lines and instrumentations in the
RO system.
3.6 Over-pressurisation caused by low
pressure isolation
If both LP In and LP Out lines of the MPE70 is
blocked and the MPE 70 is exposed to
high-pressure, there is a risk that the LP
piping could be damaged by over-pressuri-
sation.
To prevent such over-pressurisation,
appropriate relief valves should be
installed in the LP side or procedures
should be implemented to assure that
the HP of the MPE 70 is depressurised
prior to the isolation of the LP side.