Expansion joints for HV AC systems, sound absorption and vibration absorption
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Expansion joints for HVAC systems, sound absorption and vibration absorption

Product portfolio overview Axial steel expansion joints 15 Sound absorbing expansion joints 17 Rubber expansion joints 19 Technical data Axial steel expansion joints 25 Sound absorbing expansion joints 44 Rubber expansion joints 48 Installation instructions Steel expansion joints 68 Rubber expansion joints 78 Expansion joint data sheet 95

General expansion joints Depending on their physical properties, most materials expand when their temperature is increased and contract when the temperature falls. In pipe systems, this process is essentially made apparent by length changes in the individual pipe runs. As, in general, pipes are fixed at at least two connection points, reactions to inhibited thermal expansion inevitably occur, with a corresponding increase in stresses in the material and reaction forces at the connection points. If the boundary conditions allow, in general an attempt is made to absorb the pipe expansion,...

General expansion joints Axial expansion joints FP D FL FL Axial expansion joints are suitable for absorbing axial expansions (lengthening) in straight lengths of pipes. In addition, axial expansion joints are used – to absorb vibrations and reduce structure-borne noise in pumps and compressors – as flexible gaskets at the end of jacketed pipes in district heating systems – in flue gas conduits of boilers and motors, for thermal expansion and vibrations – as a disassembly joint at pumps, valves and plate heat exchangers – for gas-tight wall penetrations of pipes in nuclear reactor...

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General expansion joints If high-frequency vibrations, turbulence or high flow velocities are to be expected in the fluid, we recommend the installation of expansion joints with inner sleeve. The enclosed diagram: “Guideline for the use of an inner sleeve”, shows the limit curves for steam and gas and for liquids, above which use of inner sleeves is absolutely recommended. Use of inner sleeves helps to protect the bellows and reduces its flow-induced vibrational excitation and deposits and wear. 10 9 8 Steam / gas 7 6 Flow velocity v [m/s] ⌬Ro = calculated pipe movement (mm) Lo = Length of...

General expansion joints The task of anchor points in pipes is to safely and reliably absorb the forces that occur in the pipe and to assign the thermal expansion to the individual pipe sections. The main stresses and loads, which have to be absorbed by the anchor points if unrestrained expansion joints are: 1. Pressure thrust FDR 2. Bellows’ inherent resistance FE 3. Frictional forces FLR Re 1. The pressure thrust tries to pull the expansion joint bellows apart. As, in almost all cases, the pressure thrust is far larger than the bellows’ inherent resistance, it is not possible for...

General expansion joints Anchor load A differentiation is made between the main anchors and intermediate anchors. Main anchors are always found at the start and end of the pipe and at bends (change of direction of the pipe) and branches, i.e. where the full reaction forces occur (Fig. 2). FH = FDR + FE + ⌺FLR [N] The pressure thrust is practically removed from the intermediate anchors and axially these only absorb the inherent resistance of the expansion joint and the friction forces from the pipe guides. Note: If, for structural or space reasons, it is not possible to set any anchors,...

General expansion joints In the context of sound insulation and vibration absorbers, mechanical vibrations are within the frequency range up to the audible limit (Fig. 1). Mechanical vibrations are generated in units and are transmitted through the fluid, but mainly through the pipe, in the entire pipe system. noise, and on the other hand they cause large stresses in the materials subjected to the vibrations. In the case of pipes laid without sound insulation and/or vibration absorbers, fractures and failures can very soon occur, which endanger the operating safety and economic efficiency...

General expansion joints Low-noise plant By choosing the right expansion joint and its optimum positioning see installation instructions), you have taken the most important measures to prevent the propagation of vibrations in the pipe system. However, to achieve the objective of lownoise plant, the following problem areas must also be solved: The vibration source When choosing the unit, attention must be paid to the most quietly and smoothly running appliance. Transfer to the building or engineering structure Units, which generate mechanical vibrations transfer them to the building as...

General metal hoses The range of metal hoses kept in stock includes all products in the standard diameters, dimensions and materials, which are used in Gas installation Heating installation Cooling systems Allowable operating temperatur tB [°C]: Operating temperature of a hose assembly, which results from the max. allowable operating temperature of the weakest component or the weakest connection. Temperature factor tP: Factor for reduction of the allowable operating pressure. It corrects the allowable calculated strength of the metal hose material depending on the material used and the...

General metal hoses Allowable operating pressure pB Effect of the operating temperature The design pressure given in the technical tables relates to a temperature of 20 °C. At higher operating temperatures, due to the drop in strength of the hose materials, the allowable operating pressure pB must be reduced by the respective temperature factor tP given in the following table. Temperature reduction factors tP Temp. [°C] 1.4301 ISO 11 1.4541 ISO 15 1.4404 ISO 19 1.4435 ISO 19 a 1.4571 ISO 21 Effect of the type of operation If hose assemblies are installed in operating systems in which...