What is the primary function of boiler stays?

The primary function of boiler stays is to support flat surfaces in a boiler. Stays are structural members, often made of steel, that are used to provide mechanical support to the walls and surfaces of the boiler. These components are essential because they help maintain the structural integrity of the boiler under pressure and heat. By providing support, stays help distribute the stresses that occur during operation, preventing deformation and potential failure of the boiler's structure.

In contrast, other options focus on different aspects of boiler function and maintenance. While increasing efficiency, preventing leaks, or facilitating maintenance are important considerations in boiler operation, they do not directly relate to the primary function of stays. Stays are specifically designed to support and reinforce the physical structure, ensuring that the boiler can operate safely and effectively under its intended conditions.