Most hydraulic engineers would admit that the Darcy-Weisbach equation is the most theoretically correct equation for head loss in pipe flow. It is based on a force balance between the driving forces of pressure and gravity, offset by head loss and can be applied to any Newtonian fluid. It’s pretty elegant looking.
A dependable solution, like WaterGEMS, will increase your returns by saving on time spent on tasks and, therefore, cutting back on your project’s budget.
OpenFlows WaterGEMS offers a set of features that that make water network design easier, including an unmatched platform interoperability (CAD & GIS) and Scenario Management tools.
Pretty much all well-run water utilities periodically develop a master plan. The plan looks out 20, 30, 40 years and tries to layout development in source, treatment, and distribution systems. Based on the best available demand forecast, pipes, tanks, and pumps are laid out to evolve the system efficiently.
In most water systems, the tank water levels “float on the system” (orange system in the profile below). The HGL in the tank is the same as the nominal hydraulic grade in the system.
Over the years, modelers have developed a range of methods for taking limited demand data and developing well-calibrated models. For example, OpenFlows WaterGEMS’s Load Builder has 12 different methods for loading demands based primarily on the source of data.
Read Tom Walski’s blog to learn about inner, outer, and nominal pipe diameter and the differences these pipe diameters have in your hydraulic modeling. Various types of concrete pipe are the exception to this table in that such pipe is essentially designer pipe where the pressure class depends much more on the prestressing wire rather than the thickness of the concrete, which is really there to prevent the pipe from being crushed. For such pipe, the nominal diameter is close to the ID.
Disinfectants like chlorine and chloramines work by oxidizing chemicals and microbes in the water, and that’s why we use them. The problem is that by doing their job, their concentration decreases, and it’s possible to end up with low or zero levels of disinfectant residuals. You can’t continuously monitor residuals everywhere in your system. Your OpenFlows WaterGEMS and OpenFlows WaterCAD models can help you determine residual disinfectant levels throughout the system, identify problems and develop approaches to maintain residuals such as changing dosing, switching disinfectants, adding booster stations, flushing, and blowoffs, …
NPSHr is a property of the pump and is a function of the flow. This value is determined by testing done by the manufacturer and is usually presented as one of the pump characteristic curves. You want to ensure that the available NPSH (NPSHa) is greater than the required NPSH (NPSHr), or the water will vaporize in the pump and damage the pump.