Valve Cuts NVH in GDI Engines

April 1, 2022

Gregg Shanley

Check valve's location in the GDI fueling system.

When a leading automotive manufacturer struggled with the release of a new fuel-injection engine technology, the company required an immediate solution to maintain launch scheduling, not to mention corporate reputation. Increasingly stringent global emissions regulations have led many OEMs to implement gasoline direct-injection (GDI) fueling technology, which provides improved fuel economy, reduce emissions, and increase power. But GDI can bring problems.

The automaker found pressure pulsations in the engine’s low-pressure fuel line, upstream of the single-piston high- pressure pump that pressurizes the GDI injectors. Under certain driving conditions these pulsations created noise, vibration, and harshness (NVH) issues for the customer and fatigue-wear issues in the low-pressure fuel system. The problems – identified 10 months prior to the planned vehicle launch – could lead to significant schedule delays.

The Lee Company’s engineering team met with the OEM to discuss the problem, the system layout, mounting options and the high-level performance requirements. The automaker envisioned a component that would dampen pressure spikes returning to the tank, provide a thermal relief function, have a negligible effect on flow to the high-pressure pump, and fit within their system.

In less than a week, Lee engineers designed, built and delivered a uniquely engineered potential solution: a check valve in the fuel line. Testing confirmed the check valve solved the performance problems, reducing the pressure pulsations by up to 90% while fitting within the existing fuel line. The system with the new check valve met all other performance requirements. Over the next six months, the engineers designed and fabricated a completely new production line, supplied Production Part Approval Process (PPAP) parts and initiated production.

The check valve that helped to dampen the pressure spikes is a multi-function valve that combines the performance of a check valve, a pressure dampening restrictor and a thermal relief function, the company said. Conveniently, the valve is easy to install and doesn’t require customized mounting equipment – or add potential external leak paths within the fuel system. The innovative valve can be added to the fuel system to dampen residual pressure pulsations discharged from the high-pressure pump and virtually eliminate NVH and fatigue wear on the low-pressure pump.

The quick transition from initial design concept, through validation and into production helped the OEM launch the vehicle on schedule and safeguard their reputation. Since this initial application, the fuel-line check valve has been adopted by multiple global OEMs. The company said designs are available for a variety of standard fuel-hose materials and sizes and this valve has been proven a reliable solution to any pressure dampening application. There currently are more than 35 million currently in use. To learn more, contact The Lee Company at www.theleeco.com/contact .

Gregg Shanley, Technical Marketing Manager for the Automotive and Industrial markets, The Lee Company.