Urea pipes (for SCR only)
Galvanised steel pipe, brass and copper compo-
nents must not be used for the piping of the sys-
tem.
Proposed material (EN)
X6CrNiMoTi17-12-2
All modules are check regarding pressure and tight-
ness.
For handling the catalyst elements sufficient space
and supply tracks have to be foreseen. Depending
on the amount of catalyst elements transport devi-
ces like carriages, pulleys, fork lifter or elevators are
required.
A service space of recommended 800 mm in front
of the inspection doors of the reactor for mounting
and dismounting the catalyst elements has to be
foreseen. Further 750 mm space for service and
maintenance of the soot blower equipment and the
differential pressure device has to be considered
according the installation side of the soot blowing
system.
In case of a bend before the reactor inlet, a straight
inlet duct to the reactor of 0.5 times exhaust gas
pipe diameter and a bend radius of 1.5 times
exhaust gas pipe diameters has to be considered.
The mixing unit is designed for vertical or horizontal
installation. Bend on the downstream side has to be
in accordance to above mentioned “Reactor and
Piping”. Upstream of the mixing unit a bend can be
installed according the MAN Diesel & Turbo require-
ments mentioned on the planning drawing.
All parts mentioned in this paragraph are not MAN
Diesel & Turbo scope of supply.
All piping's have to be in accordance with
descrip-
tions P 69 00 0, 3700402-0, "Pipeline treatment
requirements for piping manufacture" and
010.000.001-01, "Operating Fluid Systems, flushing
and cleaning"
.
Piping for fluids shall be mounted in an increasing/
decreasing way. Siphons should be avoided, drain-
age system be foreseen.
The complete inside wall of the exhaust gas piping
between engine outlet and SCR reactor inlet should
not be coated by any protection material. Poisoning
of the catalyst honeycombs could occur.
All materials used for the construction of tanks and
containers including tubes, valves and fittings for
storage, transportation and handling must be com-
patible with urea 40 % solution to avoid any con-
tamination of urea and corrosion of device used. In
order to guarantee the urea quality the following
materials for tank, pipes and fittings are compatible:
Stainless steel (1.4301 or 1.4509) or urea-resistant
plastics (e.g. PA12). For gaskets EPDM or HNBR.
Piping for compressed air see section Specification
of materials for piping.
Unsuitable materials for tank, pipes and fittings are
among others: Aluminum, unalloyed steel, galvan-
ised steel, copper and brass.
In case incompatible material is used, clogging of
urea filter inside the pump module may occur, or
even worse, the catalyst elements may be dam-
aged by catalyst poisons derived from this material.
In this case, exchanging the catalyst modules may
be necessary.
Store this material in cool, dry, well-ventilated areas.
Do not store at temperatures below 10 °C and
above 55 °C. The storage capacity of the urea tank
should be designed depending on ship load profile
and bunker cycle.
The urea supply line should be provided with a
strainer and a non-return valve in order to assure a
correct performance for the suction of the urea
pump, which is installed downstream the tank. A
level switch with the possibility to read out the signal
will protect the pump of a dry run. A return line from
the urea pump module over a pressure relief valve is
entering the tank.
Use of good quality urea is essential for the opera-
tion of an SCR catalyst. Using urea not complying
with the specification below e.g. agricultural urea,
can either cause direct operational problems or long
term problems like deactivation of the catalyst. For
quality requirements, see section Specification of
urea solution.
The quality of the insulation has to be in accordance
with the safety requirements. All insulations for serv-
ice and maintenance spaces have to be dismounta-
ble. The delivered modules have no fixations, if fixa-
tions are necessary take care about the permissible
material combination. Regarding max. permissible
thermal loss see section Boundary conditions for
SCR operation.
MAN Diesel & Turbo
3700467-8.1
Page 15 (17)
SCR (Selective Catalytic Reduction)
B1600 0
V28/32S, L28/32S, L28/32H, L27/38S, L27/38, L23/30S, L23/30H, L21/31S,
L21/31, L16/24S, L16/24
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