ELBOW 4374052 - Caterpillar

Table 6
Approximate Weights Of Serviceable Parts
Component C280-08 Engine
Cylinder block 5584 kg (12300 lb)
Bearing cap 65 kg (144 lb)
Crankshaft 2288 kg (5034 lb)
Flywheel assembly 491 kg (1080 lb)
Crankshaft vibration damper 267 kg (588 lb)
Cylinder head assembly 235 kg (517 lb)
Cylinder liner 128 kg (282 lb)
Piston assembly 36 kg (77 lb)
Piston pin 19 kg (42 lb)
Piston rod assembly 57 kg (125 lb)
Turbocharger 401 kg (883 lb)
Aftercooler core (1) 36 kg (80 lb)
Unit injector 12 kg (27 lb)
Front housing 258 kg (568 lb)
Rear housing 222 kg (488 lb)
Used air cleaner element 35 kg (78 lb)
(1) The weight is listed for a single-stage aftercooler. A two-stage aftercooler and an aftercooler with a deep core are also available.
Table 7
Approximate Weights Of Aftertreatment System Components for C280-08 Engine
Aftertreatment Components Weight
SCR reactor housing (CEM)(1) 1741 kg (3838 lb)
Single catalyst assembly 21.5 kg (47.3 lb)
Service/access door 24 kg (53 lb)
Mixing pipe 136 kg (300 lb)
DEF injector lance assembly 5.78 kg (12.7 lb)
Dosing cabinet 90 kg (198 lb)
(1) Without catalyst assembliesAftertreatment system description
Illustration 6 g03498661
Caterpillar supplied aftertreatment components are illustrated with dashed line rectangles.
Selective Catalyst Reduction (SCR) catalyst technology is used to reduce NOx emissions and particulate matter (PM).The aftertreatment system is composed of the following components:
Diesel Exhaust Fluid (DEF)
Dosing cabinet
Mixing tube
SCR reactor housing
SCR catalystsEngine exhaust flows into the SCR System reactor housing through the exhaust inlet. Once sufficient temperature is achieved, the DEF is injected into the exhaust. Exhaust flows through a mixer assembly in the mixing tube to ensure that exhaust is stratified for uniformity. This mixing will ensure complete disbursement across SCR catalyst section. Precise DEF injection is monitored and controlled by an electronic controller in the dosing cabinet. The following components provide signals to the controller to control DEF injection for emission reduction:
Thermocouple located in the reactor housing.
Post NOx sensor
Pre NOx sensor is located in the mixing tube upstream of reactor housing.DEF fluid is injected into the exhaust stream before entering the SCR. When injected into the exhaust stream, the DEF is atomized into droplets. The atomized droplets are then sent through the mixer. The mixer disrupts the exhaust flow and allows DEF to be distributed throughout the exhaust gas. Water evaporates due to the high temperature of the exhaust and releases ammonia (NH3) that was bound to the DEF. NH3 is free to react with the NOX and the oxygen present in the exhaust system stream. This reaction occurs on the SCR catalyst. NH3 and NOX are converted into gas particles of nitrogen and water.Dosing Cabinet
The dosing control cabinet controls the following:
Rate of DEF flow to the injector
Compressed air pressureThe dosing cabinet houses the following:
Pump
ECM
Sensors
Manifold
DEF tank
Valves
HeatersCat engine ECM and the aftertreatment ECM located in the dosing cabinet are designed to communicate with each other. This communication controls the complete engine/emission system to meet emission levels.DEF Tank
A DEF low-level sensor is located in the main DEF tank. If the DEF level in the main