The minimum pitch diameter of block hoisting sheaves should be at least how many times the rope diameter?

The minimum pitch diameter of block hoisting sheaves should be at least 16 times the rope diameter to ensure proper operation and to maximize the lifespan of both the sheave and the rope. This specification is crucial because a larger pitch diameter reduces the bending stress the rope experiences as it travels over the sheave.

When the pitch diameter is too small relative to the rope diameter, it can lead to increased wear, potential damage, and a higher risk of failure. This guideline is grounded in industry standards that focus on optimizing performance while ensuring safety and durability in lifting applications. Using a pitch diameter of at least 16 times the rope diameter ensures that the sheaves function effectively, leading to smoother operation and extending the service life of the rope.