Compensator (expansion joint or loop)

To add a new compensator (expansion joint or loop), click the button  of Components toolbar or use the corresponding item of "Insert - Component" menu. Please note that the new component is added to the project tree after the currently selected element. Therefore, to add a new component after an existing one, select it in the project tree or in the graphic window and add the new component. If you need to add a new component to the beginning of a branch, select the branch in the project tree and add the new component.

After adding a compensator, its characteristics will be displayed in the Object Properties Window:

• hydraulic component type/dimensions - here you need to select one of the following types of compensators and, if necessary, enter their geometric dimensions:

• name - by default, the name of any piping component coincides with its type, but if necessary, the name can be changed in this field. When changing the hydraulic component type (when selecting different types of compensators), its name will also change, but only if it has not been previously changed to another manually. Specify the name that you would like to see for this element in reports with calculation results. To display the name of a pipeline element on the diagram, click the corresponding button to the right of its name;

• quantity - this parameter is used in cases when it is necessary to simulate and calculate the resistance and heat losses of several compensators of the same type, without specifying each of them separately. To do this, enter the number of such compensators in this field, and during the calculation, the hydraulic resistances and heat losses on this compensator will be multiplied by the specified value. Of course, not all compensators will be displayed on the graphical diagram (only one of them will be displayed), but they will be taken into account in the calculation. However, it is important to note that this method of setting not always gives a good accuracy of calculation, since it does not take into account that a change in pressure and temperature after the next piping component may entail a change in the density and viscosity of the fluid (which is especially crucial for gases and gas-liquid mixtures), and, consequently, a change in the pressure drop on subsequent elements. This method can be used for a quick rough estimate and mainly for liquids, the properties of which don't change (for instance, at a constant temperature) or change slightly along the pipeline. For a more accurate calculation, you should specify all components sequentially in the exact order they appear (even if there are repeating ones among them);

Please note that from a hydraulic point of view, a lens expansion joint is considered as a "point" (or "concentrated") resistance that has no length. Therefore, if it is necessary to take into account the dimensions of such a compensator in the calculation (to calculate and account for the friction losses, heat losses and hydrostatic pressure drop that occur on it), they can be modeled separately as a piece of pipe with the corresponding length, or the length of the compensator can be added to the lengths of the pipes adjacent to the compensator. However, this only makes sense in cases where the expansion joint:

• has really large size that cannot be neglected;

• is located in a vertical or inclined plane relative to the vertical - in this case, it is important to take into account the hydrostatic pressure drop that occurs on it;

• is located in a closed loop (so that the piping model looks correctly, without gaps).

In other cases, friction losses on the bellows/lens expansion joint (and therefore its length) are usually neglected.

As for the U-type expansion loop, from a hydraulic point of view it is considered as a "dimensional" resistance (i.e., having a length). This must be taken into account when specifying the pipes adjacent to it, indicating their actual lengths as the dimensions of these pipes (for more information, see here). The total length of the compensator (taking into account the pipes and the lengths of the bend arcs) will be displayed in the calculation results.

When drawing a U-type compensator on a pipeline graphic diagram, the direction of its extension is determined by the program arbitrarily and cannot be changed. However, it should be noted that this not affects the calculation results.