STEP GP 3559822 - Caterpillar

Retrofit Aftertreatment:
SCR (S/N: ES71-UP)
Engine News SEBD9918, 12 December 2013, "New SCR Retrofit Aftertreatment Systems". The original article has been revised to change the title. Refer to the article below.Description of Change: The reactor used on retrofit SCR systems are designed with double wall construction. A recent production change has eliminated the insulation material between the two walls. The air gap remains and provides an insulating effect. This change allows for an increase in reactor surface temperature over the former design that used insulation material.Adaptable To: The reactor is an exhaust system component that can have surface temperatures that exceed 166° C (330° F). Companies responsible for the facilities should consider all issues related to hot surface access during the installation process. Use proper external insulation to cover areas that are susceptible to flammables or inadvertent human contact. Some applications may consider alternate means of reducing heat effects from the aftertreatment system such as the use of heat shieldsDo not remove the insulation from the reactor unless there is a need for service and the increased surface temperature is acceptable in the application. The increased temperature varies based on the application and location of the reactor. Testing indicated that the average reactor surface temperature increased approximately 25° C (77° F)Refer to Assembly and Installation Guide, LEBE0033for additional installation details.The change is effective with serial number ES700274-UP.