PISTON ASSEM. 7S6792 - Caterpillar

General Information
Diesel Exhaust Fluid (DEF) is a liquid that is injected into the exhaust system of engines equipped with Selective Catalytic Reduction (SCR) systems. SCR reduces emissions of nitrogen oxides (NOx) in diesel engine exhaust.Diesel Exhaust Fluid (DEF) is available in many brands, including those brands that carry the AdBlue or API certification. DEF is also generically referred to as urea.In engines equipped with SCR emissions reduction system, DEF is injected in controlled amounts into the engine exhaust stream. At the elevated exhaust temperature, urea in DEF is converted to ammonia. The ammonia chemically reacts with NOx in diesel exhaust in the presence of the SCR catalyst. The reaction converts NOx into harmless nitrogen (N2) and water (H2O).Note: Follow all applicable industry standards and all applicable governmental, environmental, safety guidelines, practices, regulations, and mandates.Note: These general recommendations and guidelines concerning maintenance and care of DEF and DEF storage systems are not intended to be all inclusive. Discuss proper DEF safety, health, handling, and maintenance practices with your DEF supplier. Use of these general recommendations and guidelines does not lessen the responsibility of the engine owner and/or DEF supplier to follow all industry standard practices for DEF storage and for DEF handling.Characteristics of DEF and Urea Fluids
DEF solutions are typically of 32.5 percent concentration urea. However, some marine engines may use DEF (32.5 percent urea concentration) or urea solutions of 40 percent concentration. All DEF solutions that are of 32.5 percent urea must meet all the requirements defined by the "ISO 22241-1" standard.The caps of DEF tanks are blue, as required by emissions regulations. Fill DEF only in clearly marked DEF tanks that have the blue cap.Caterpillar recommends the use of DEF available through the Cat parts ordering system for use in Cat engines equipped with SCR systems. Refer to Table 1 for part number information:
Table 1
Cat Part Number (32.5% Urea)    Container Size    
350-8733     2.5 gal bottle    
350-8734     1000-L tote    In North America, commercial DEF of 32.5 percent urea concentration that is API approved and meets all the requirements defined in "ISO 22241-1" may be used in Cat engines that are equipped with SCR systems.Outside of North America, commercial DEF of 32.5 percent urea concentration that meets all requirements defined in "ISO 22241-1" may be used in Cat engines that are equipped with SCR systems.The supplier should provide documentation to prove the DEF is compliant with the requirements of "ISO 22241-1".
Cat does not warrant the quality or performance of non-Cat fluids.
Do not use agriculture grade urea solutions. Do not use any DEF 32.5 percent fluid that does not meet "ISO 22241-1" Requirements in SCR emissions reduction systems. Use of these fluids can result in numerous problems including damage to SCR equipment and a reduction in NOx conversion efficiency.
DEF is a solution of solid urea that is dissolved in demineralized water to produce a final concentration of 32.5 percent urea. Most SCR systems are designed to operate only on DEF concentration of 32.5 percent.