What Happens When the Power Drops Out?
Pump stations are fed by the power grid, so when the power goes out, it also goes out for water pumping stations. And water utilities don’t like their systems losing pressure.
Success Story | Blackwell Group Picks CivilStorm for Their Stormwater Modeling Solution
The Blackwell Group is a multidisciplinary engineering firm located in Virginia that performs work in the residential, commercial, and government sectors. Stormwater design and site grading are just a few of the many services that Blackwell Group offers. In a typical stormwater project, the Blackwell Group designs a grading plan for a proposed redevelopment or new development. While creating the grading plan, they evaluate stormwater impacts of both pre- and post-development by performing hydrologic studies for the 2-, 10-, and 100-year storm events.
Are Your Pressure Gauges Calibrated?
Pumps & Systems magazine had a good article recently on the need to calibrate pressure gauges. They pointed out that pressure gauges (and sensors) tend to lose accuracy over time; specifically, that gauges should be calibrated at a regular interval, suggesting annually as typical.
Visualizing Pressure Zones
Pressure zones are important but can be difficult to understand. OpenFlow WaterGEMS and OpenFlows WaterCAD makes creating and managing pressure zones easy.
Including Disinfection By-Products in a Multi-Species Decay Model to Support Cost-Effective Chlorination
In the blog A Multi-Species Decay Model to Support Cost-Effective Chlorination in Distribution Systems, a cost-effective chlorination strategy is defined as the least-cost combination of doses (locations and rates) that achieves effective chlorination for a given stable flow regime and water temperature. Searching for such a strategy requires extended-period simulations for many dosing location and rate combinations.
What’s So Bad (Or Good) About The Colebrook-White Equation?
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.
The Most Important Decision – Why Tanks Matter
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.
What is NPSH(required)?
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.
Pump Configuration Toolbox
Picking the right number of pumps and which ones to run at any time without wasting energy is tricky. The problem gets especially tricky when you have the potential to mix constant and variable speed pumps, and there is no storage in the system, so you can’t simply run pumps efficiently and turn them off when a tank is full.
Extending Pump Curves
A key input to any model with pumps is some form of pump head curve showing flow vs. pump head. Given the curve, the model can tell the user the exact point on the pump curve at which the pump will operate.