WinGD X72 - Function; SCR System Bypassed (Tier II)

Operation9270−1/A1
Winterthur Gas & Diesel Ltd.
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2. Function
2.1 SCR System Bypassed (Tier II)
The engine operates in Tier II mode without SCR, see Fig. 3.
The valve V3 is fully open and the valves V1 and V2 are fully closed. Urea solution is
not injected.
To prevent an exhaust gas leak through valve V1 or V2 into the SCR pipe, a vent unit
supplies air into the SCR pipe during bypass operation.
Engine
V1
V2
V3
V7
V4
Turbocharger
SCR Reactor
Air pipes − flow
Exhaust pipes − no flow
Exhaust pipes − flow
WCH03721
Fig. 3: SCR System Bypassed
2016−11
Selective Catalytic Reduction System