# Size Change Components

When modelling Size Change components such as Thin Orifice Plates, Thick Orifice Plates, Venturi Tubes, Inline Nozzles, etc., we have the option of setting the Status of these nodes to Ignore Pressure Loss. By selecting this Status, the software will skip the pressure loss calculation associated with the element. It should be noted that if Ignore Pressure Loss has been selected, the stagnation and static pressures at the element inlet and outlet will be identical. However, as we have a restriction in the line, the velocity will increase across the element which will result in an increase in the associated velocity pressure. Since the stagnation pressure across the element will be constant, if the fluid velocity and velocity pressure increases considerably, the static pressure across the element may be negative (conservation of energy laws). Users may wish to review the design and data entry in further detail if this scenario arises.