Which of the following is NOT a type of stay used in boilers?

In the context of boiler construction, stays are structural components that help maintain the integrity and shape of the boiler under pressure and temperature changes. Common types of stays include various configurations like T stays, Y stays, and J stays, each designed to fulfill specific requirements in terms of support and load distribution.

T stays are shaped like the letter T and are typically used in horizontal boilers to provide support between the top and bottom portions. Y stays have a shape resembling the letter Y and are utilized for similar reasons, often providing support in areas where stress is concentrated. J stays, which are similar to T and Y stays but with a different configuration, are also used for lateral support in the construction of boilers.

In contrast, V stays are not recognized as a standard type of stay in boiler design. This distinguishes them from the other types mentioned, making them the correct answer to the question regarding which type is NOT used in boilers. The absence of V stays in typical boiler design principles solidifies its status as an incorrect option in this context.