Assumptions:
1. Steady Flow: The flow of fluid in the pipe is assumed to be steady, meaning that the flow velocity and pressure do not change with time.

2. Incompressible Fluid: The fluid is incompressible, which is generally applicable to liquids and results in constant density throughout the flow.

3. Fully Developed Flow: It is assumed that the flow is fully developed, meaning that the velocity profile is stable and does not change along the length of the pipe.

4. Constant Pipe Diameter: The pipe is considered to have a constant diameter, allowing for uniform flow characteristics throughout the pipe.

5. Single-Phase Flow: The calculations assume single-phase flow, which means that the fluid is entirely in one phase, with no phase change occurring.

6. Negligible Pipe Fittings: The calculator typically does not account for additional losses due to pipe fittings, bends, or valves.