Intake/Exhaust Systems Waukesha gas engines Exhaust System Installation Guidelines Page 1 of 6 Exhaust System Installation Guidelines EN: 157564-01 DATE: 3/15 Ref. S 8242 Intake/Exhaust Systems Waukesha gas engines FLEX CONNECTION EXHAUST SUPPORT STRUCTURE -CUSTOMER SUPPLIED(SEE NOTE 14) VHP P9394 ENGINE Page 2 of 6 Exhaust System Installation Guidelines EN: 157564-01 DATE: 3/15 Ref. S 8242 Intake/Exhaust Systems Waukesha gas engines 1. Allow for thermal expansion of the exhaust pipe beyond the Waukesha* flex. The Waukesha exhaust flex (when supplied) will accommodate engine thermal expansion but cannot tolerate movement imposed by external thermal growth. Insulated pipes will run hotter and consequently expand more. COEFFICIENT OF EXPANSION Steel 0.00065 in/in/100°F Stainless steel 0.00099 in/in/100°F EXAMPLE: 10 ft. of steel pipe on a L7042G with an exhaust temperature of 1060°F will expand based on 60°F ambient. (0.00065 in/in/100°F) (10 ft) (12 in/ft) (1060°-60°/100 ) = .78 in. 2. Remember that a flex connection has “spring constants” (lateral, axial, radial, torsional) that should be considered when engineering the exhaust system. Transmission of forces to the engine exhaust system (engine exhaust flange) must be nil. (Any specific load or bending moment limits shown on an engine’s installation drawing must not be exceeded.) 3. Design the exhaust system so it will not impose torsional forces on the exhaust flex connection. 4. The exhaust flex connection should be designed to allow for flexing caused by engine operation, acceleration, deceleration, starting and stopping. The Waukesha exhaust flex (when supplied) will accommodate engine vibrations with a solidly mounted unit, but cannot tolerate the additional forces/displacement imposed by mounting on spring isolators. Additional flex capabilities will be required when the unit is mounted on isolators. 5. Consider expected life. Cyclic flexing can lead to premature failure by causing fatigue breakage. 6. Utilize a combination of fixed supports, rollers and flex connections to provide a well designed exhaust system. See sketches for additional concepts. 7. Provide water traps/drains to prevent exhaust condensation and/or rain from reaching the engine. This is especially true on long pipe runs. Use rain caps where applicable. Slope piping away from engine. Page 3 of 6 Exhaust System Installation Guidelines EN: 157564-01 DATE: 3/15 Ref. S 8242 Intake/Exhaust Systems Waukesha gas engines AXIAL RADIAL 8. The minimum requirements for the design of the exhaust system should be to contain explosions that could be encountered during the operation of the engine. Waukesha recommends the use of carbon steel schedule 20 pipe as a minimum. Stainless steel schedule 10 pipe is preferred because of its greater strength properties at elevated temperatures. Waukesha does not recommend using double walled piping or slip joints on engine exhausts. 9. Utilize smooth transition to final pipe size when a transition in size is required. Waukesha recommends a diverging angle of 15 degrees for low pressure drop (see sketches for straight and elbowed transitions). 10. Engines with two exhaust outlets combined into one (such as 12VAT25GL engine) must have a symmetrical design up to and including the point of convergence of the two exhaust streams to produce proper flow and restriction balance. Convergence angle from the center of symmetry must not exceed 45 degrees. The outlet area of the y-connection must be equal to or greater than LATERAL TORSIONAL the sum of the two inlet areas. 11. Size piping and silencer so that exhaust system back pressure, as measured at the engine outlet flange, is less than that indicated in the specifications page in the tech data book. 12. Provide clearance to permit use of a chain hoist for removal of heavy components. 13. For other exhaust system parameters see chapter seven, (Exhaust System) of the “Waukesha Installation Manual” (Form 1091. 14. For the VHP P9394 Engine, the support structure can be built – if required. Maximum load of 240 lbs total (60 lbs per bracket) cannot be exceeded at any time. This includes the weight of the support structure, Engine supplied exhaust components and thermal growth. Loads to be equalized between brackets. Thermal growth must be considered and to be in direction shown Page 4 of 6 Exhaust System Installation Guidelines EN: 157564-01 DATE: 3/15 Ref. S 8242 Intake/Exhaust Systems Waukesha gas engines The dual outlets shown below violate the symmetry requirement or have a converging angle which exceeds 45° potentially causing high or unbalanced restriction. Page 5 of 6 Exhaust System Installation Guidelines EN: 157564-01 DATE: 3/15 Ref. S 8242 Intake/Exhaust Systems Waukesha gas engines *Trademark of INNIO. All other trademarks are the property of their respective owners. Page 6 of 6 Exhaust System Installation Guidelines EN: 157564-01 DATE: 3/15 Ref. S 8242
