The optimum installation torque – challenges and opportunities of virtual engineering

Achieving the right installation torque with a virtual calculation

Determining the required installation torque for a tight flange system is a daily challenge for industrial valve manufacturers and plant operators alike. All of the components in the flange system have their own individual installation requirements. Environmental requirements, such as evidence according to TA Luft, add further difficulty to the project. The collaboration between manufacturers of individual components and the plant operator for a holistic approach is crucial to bring everything into harmony.

The German rupture disc manufacturer REMBE already recognised this task at an early stage and has long been committed to complying with its customers’ installation requirements. What exactly this challenge entails and what possible solutions are available are described in this article.

There are generally different approaches when it comes to selecting the required installation torque. Alongside manufacturer information for individual components, there are calculation standards such as DIN EN 1591-1 or the AD 2000 set of rules, with which conventional flange systems can be calculated analytically. A conventional flange system (see figure 1, left) according to the stated calculation standards is defined as a flange inlet (flange I), flange outlet (flange O), gasket and connecting elements (e.g. bolts). In practice, a flange system is often expanded by additional components (cf. figure 1, right). This can be a pressure protection mechanism, such as a rupture disc. A rupture disc is usually installed with a mounting unit (hereinafter called a holder), consisting of a holder inlet (holder I) and holder outlet (holder O). A second gasket (gasket I) is also required. In this case, four additional components must be taken into account at once.

The conventional/stated calculation standards become invalid for these expanded flange systems as the equations underlying these standards do not take any additional components into account

All of the required calculations stated above for configuring the installation torque cannot currently be performed with sufficient precision using analytical calculation principles. In order to take into account, the complexity and the ever greater challenges on the configuration of the installation torque, REMBE makes use of virtual engineering with the finite elements method. This makes it possible to depict the flange system including all (additional) components as a digital twin and thus simulate its mechanical behaviour before manufacture and commissioning. With this digital twin, the mutual influences of all of the components are thus taken into account in advance before being brought together in reality.