Flow turn

To add a new flow turn, 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.

The flow turn element is used to simulate the resistance of the sharp flow turn (in contrast to a bend, where usually the flow turns smoothly).

After adding a flow turn, 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 flow turns and, if necessary, enter their geometric dimensions:

The specified values of the new inner and outer diameters of the flow turn niche after the turn are applied to all components of the branch after this component until the end of the branch or until the next component with a diameter change (if there is one in this branch). Please note that when adding and deleting such flow turns (with a change of diameter), as well as when changing their new diameter value, the program will not only automatically adjust the values of the diameters of all the following components in this branch (up to the first element with a change in diameter if any), but will also change the values of the radii of the bends and elbows in this branch if they are equal to the standard value of 1.5*DN (for pipes with DN < 500mm) or 1*DN (for pipes with DN >= 500mm).

• 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 flow turns), 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 of several identical flow turns in a branch without specifying each of them separately. To do this, you need to specify the number of such flow turns in this field, and at the calculation, the hydraulic resistance on this element will be multiplied by the specified value. Of course, not all flow turns 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 flow turn is considered as a "point" (or "concentrated") resistance that has no length. Therefore, if it is necessary to take into account the dimensions of the flow turn niches in the calculation (to calculate and account for the friction losses, heat losses and hydrostatic pressure drop that occur on them), they can be modeled separately as pieces of pipes with the corresponding lengths, or their lengths can be added to the lengths of the pipes adjacent to the flow turn. However, this only makes sense in cases where:

• the flow turn niches have really large lengths that cannot be neglected;

• one or both flow turn niches are 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 them;

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

In other cases, friction losses in flow turn niches (and therefore their lengths) are usually neglected.

It is not recommended to install flow turns as the first and last elements in a branch, since the orientation of the flow turn in space is determined by the directions of the pipes located before and after it. Therefore, if there are no pipes before and/or after the flow turn, it will be impossible to accurately determine its orientation in space, and the flow turn may be displayed incorrectly on the diagram (however, of course, this will not affect the correctness of the calculation).