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Carina Wegener, REMBE GmbH, Germany, discusses how to achieve the right installation torque with a virtual calculation.
etermining the required installation torque for a leak-tight flange system is a daily challenge for industrial valve manufacturers and plant operators alike. All of the components in the flange system have individual installation requirements, and environmental considerations add further difficulty to the task. The collaboration between the individual component manufacturers and the plant operator is crucial to everything working in harmony. This article will describe the challenge in greater detail, and outline the possible solutions that are available.
Selecting the installation torque Generally, there are 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. According to these standards, a conventional flange system (see Figure 1, left) is defined as a flange inlet, flange outlet, gasket and connecting elements (e.g. bolts). In practice, a flange system is often expanded by additional components (see 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, consisting of a holder inlet and holder outlet. A second gasket is also required. The conventional calculation standards become invalid for these expanded flange systems, as the equations underlying these standards do not take any additional components into account. Metallic sealing surface contact has also been excluded up until now, as have systems whose stiffness HYDROCARBON 63
ENGINEERING
February 2022
