Danmuff metal expansion joints, available from EagleBurgmann Australia Pty Ltd
have been specifically designed for installation in district heating pipe systems.
When the bellows is fully compressed, the axial compressive forces in the pipeline can be transferred directly through the adjoining end surfaces of the media pipes without overloading the bellows. If the temperature in the pipe network drops to such an extent that tensile stresses occur, the maximum tensile stresses in the media pipe will be transferred to the stop ring through the outer casing pipe and the contact faces of the slide guide.
Danmuff is also protected against torsion. Danmuff metal expansion joints are designed to reduce the number of fastenings in the pipe system, as the expansion joint can be installed in series in sections of pipe without intermediate fastenings.
The expansion joints will trigger each other individually. Together with the media pipe, the guide pipe forms a telescopic union in the expansion joint with regard to direction of flow. This telescopic union also forms a guide, allowing lengths of pipe to be welded together including the expansion joints, and then laid in the trench without the expansion joint being damaged.
The expansion joint is pre-stressed 100% at the factory using explosive bolts, which are fitted through the stop ring and into the slide guide. When the installation is put into operation, the explosive bolts are activated, triggering the movements of the expansion joint.
The DanOne is an axial one cycle or startup expansion joint used in pipe systems where variations in temperature around a desired mean temperature are not to be absorbed as expansion movements, but as tensile and compressive stresses in the pipe system.
DanOne expansion joints are used to complete installations without heating up the system before operation. By locking the expansion facility when the pipe system is heated up to this temperature for the first time, future expansions in the pipe system caused by variations in temperature will be absorbed as tensile and compressive stresses when the system cools down and heats up respectively in relation to the mean temperature.