Solenoid Valve Reliability

Solenoid valves are used everywhere in appliances, dispensers and industry to automate flow controls. Depending on the duty cycle requirements, these valves are either very reliable, or prone to failure. Some appliance controls cycle these valves over millions of cycles in the appliance life, so durability is a key requirement.

Cost is always an issue with appliances and similar products, so manufacturers are driven to find the lowest cost component supplier. When several units of a component are used on an appliance, unit cost can become a significant contributor to overall product cost.

The challenge on this project was to find root cause of solenoid valve failures, then work with the current and alternate suppliers to implement improvements and increase overall reliability. A Six-Sigma reliability project was undertaken to determine root cause using the classic DMAIC process. The problem was defined with inputs from customers and field service technicians. Overall scope of the problem was determined then potential root causes were brainstormed. A structured process of analysis and laboratory investigation was then undertaken to prove which candidates actually contributed to root cause, and which did not.

The team was able to determine root cause, and to determine that the current supplier could not meet reliability targets. An alternate supplier was engaged to complete the design and implementation on the product. The eventual design improvement was implemented into production at the end of the project.