SCR Surface Temperatures
Position
Thickness of
Heat Insulation
at exhaust temper-
ature of 350 °C
(662 °F) at the
SCR-muffler inlet
at exhaust temper-
ature 450 °C (842 °
F) at the SCR-muf-
fler inlet
Casing – all round
Muffler filled with
insulation
75 °C (167 °F)
125 °C (257 °F)
End wall – in/outlet side
20 mm (0.78 in)
100 °C (212 °F)
150 °C (302 °F)
End wall – other side
20 mm (0.78 in)
125 °C (257 °F)
200 °C (392 °F)
Mounting strap area
No insulation
225 °C (437 °F)
300 °C (572 °F)
The MACK SCR system is simple and effective, with few components. It consists of a aftertreatment DEF tank positioned
near the standard diesel tank, plus a aftertreatment DEF pump, aftertreatment DEF Dosing valve and a SCR catalyst. The
advantage of using DEF is that it enables the engine to use less exhaust gas recirculation (EGR) gases – and higher oxygen
levels – for better combustion, while meeting the EPA near-zero NOx emissions requirement of 0.2 g/hp-hr NOx. By using
DEF, we avoid the disadvantages of increasing EGR to massive levels. This results in better fuel economy from your MACK
engine.
W2055490
W2055491
W2116335
Vertical SCR, side inlet
Vertical SCR, bottom inlet
Vertical SCR, side inlet and outlet
W2055492
W2055493
Horizontal SCR, full size
Horizontal SCR, compact size
Mack Body Builder Instructions
CHU, CXU, GU, TD, MRU, LR
USA139046859
Date 5.2017
Body Builder; Engine, MP7, MP8, and MP10
Page 16 (43)
All Rights Reserved
