How can a flange with approximately 40% less material perform like a conventional flange?
The stress levels in the conventional flange are extremely low. Finite element proves this. When the national standards for pipe flanges were established nearly 100 years ago, flanges were sold on the basis of $/ton. Energy and resources were cheap. Curved beam theory as well as sophisticated calculation methods were not yet known. With the advent of the PC and software packages to evaluate structural elements, savings could be offered in many ways. Like in an I-beam, the ability to carry loads with less weight is being practiced. The mass removal underneath the bolt hole circle and a slight increase in section height leads to an intelligent design. IPP simply removed the material that was not being utilized.
