Which type of stay is commonly found in wet back type boilers?

Stay bolts are commonly found in wet back type boilers because they provide structural support to the boiler's shell and help maintain its shape while under pressure. Wet back boilers have a design that includes water in contact with the back portion of the boiler, which requires robust structural integrity to withstand the thermal expansion and contraction that occurs during operation. Stay bolts perform this critical function by securing the boiler plates together, thus preventing deformation and potential failure.

In wet back designs, where there is a significant amount of water and heat transfer, stay bolts ensure that the materials remain securely fastened despite the stresses from internal pressure and temperature variations. Their ability to absorb and distribute loads effectively makes them essential for maintaining the safety and efficiency of wet back boilers.