Where Performance Curves Fall Short: Solving Tier IV Engine Uncertainty with Package Curves

As emission regulations change worldwide to accommodate environmental conditions, engine owners and operators are faced with new challenges in terms of learning how to run, maintain and maximize their diesel engines. Final Tier IV engine mechanics can lead to issues in the field for pump operators and long-term maintenance concerns for equipment owners. While selecting the right pump engine is more complicated than ever, it has also never been more important. This white paper takes a closer look at package curves — a tool that helps owners and operators select the right Final Tier IV engine to meet their specific pump application needs.

What Makes Final Tier IV Engines More Complex?

Final Tier IV engines are designed around specific emission regulations: emitting less unburned fuel and particulates into the air via the engine's exhaust system. These regulations have led to more complex exhaust aftertreatment designs, and if the engine is not generating enough heat, the system could experience maintenance or performance issues.

After-treatment systems vary by manufacturer, but typically the engine has to be under high load to get the aftertreatment system to work properly. At lower speeds, the load put on the engine from the pump is reduced. Low load combined with low speeds prevents the aftertreatment system from doing its job; this can lead to unplanned service, regeneration cycles and downtime.

This is what makes correctly sizing the engine for the pump so critical.

 

How Can Owners & Operaters Assure They Are Sizing Correctly?

Traditional pump curves have been around for decades and were created as a tool to illustrate the performance range of the pump end regardless of the engine or motor powering it. For years, owners and operators have used pump curves to size an engine that covers the power required at maximum speed, usually erring on the side of oversizing.

With Final Tier IV engines, the tendency to oversize engines carries a greater upfront cost than before and can lead to increased cost of service down the road. Plus, using traditional pump curves correctly when considering Tier IV engine use often requires some technical expertise.

How do Package Curves Work?

Package curves eliminate the need for extensive technical knowledge. They specifically show what size engine will run most efficiently with a pump, while still delivering optimum performance. These curves are meant to provide the right information in the simplest way possible and do not require a Final Tier IV expert to understand them. Package curves use color coded zones to illustrate boundaries of operation for the pump and engine, as shown below.

If you wanted to run 600 gpm at 60 feet (Point 3) — would it be wise? Engine 1 would be the ideal choice. If you were running Engine 2, the curve indicates you’d be in the yellow – meaning operation at this speed should be limited. Running the engine for an hour or two might be okay; anything more, and you could run into issues.

Package Curves in Action: Selection Examples

The package curves shown demonstrate the operational zones of specific diesel engines paired with the Pioneer Prime 66S12 pump. In each case, the package curves can answer use case questions and help owners optimize which engine they’d use on-site.

For example, if you wanted to run 2,000 gpm at 80 feet (Point 1) — could you do it? The package curves show both engines operating in the green. What about 2,600 gpm at 60 feet (Point 2)? Engine 1 would be the only choice in this situation, as Engine 2 would be red/restricted operation.

 

How do Package Curves Improve Uptime and Reliability

Today’s Final Tier IV engines are more expensive and harder to repair than previous versions. Technicians are still learning about these engines, adding to uptime and reliability issues. It is more important than ever to run the engine in a way that maximizes its performance and lifespan. If an engine runs at low speed for an extended period of time, it can create problems with the engine, including shortened life, emergency service requirements, inefficient diesel  exhaust fluid (DEF) or fuel consumption, and other issues.

In fact, if a Tier IV engine isn’t used properly, it can enter into an unplanned regeneration cycle. These engines are hard coded to shut down and run an automatic maintenance cycle if too many particulates are being released. If you’re running a critical infrastructure pump — a sewer bypass, for example — downtime is unacceptable. Pump curves help owners and operators avoid the dangers associated with underloading a diesel engine.

Package curves help owners and end users operate pump packages within a safe zone — ensuring longer life, reduced maintenance costs and lower cost of ownership. They can also help personnel in the field feel more confident with Final Tier IV engines by illustrating exactly where they can and cannot operate the pump. The changes brought on by EPA regulations for Final Tier
IV have created new challenges, and by extension added time and cost into operations. These specialized package curves provide a clean and simple way to reduce uncertainty and improve performance and longevity of the product.

In terms of efficiency, the benefits go beyond operating and life span: package curves help users invest in the right-sized engine from the start. When following the package curves, users can get a correctly sized engine for the pump, which improves fuel efficiency and DEF consumption rates.