Learn the engineering, then apply it
EngiMetric is built so the explanation and the calculation are the same thing. Every topic below states what the engineering actually does, names the assumption it rests on, and links to the tool that applies it — so you can read the principle, test it against your own numbers, and then build the whole plant.
Learn explains how it works. Technology says what exists and where it fits. Tools calculate one figure. The Plant Designer builds the plant. They are deliberately separate, so you always know what kind of page you are reading.
Engineering topics
Structured subjects, each carrying the governing equations and the tools that use them. The full index, including every published topic, is on the topics index.
Reverse Osmosis
How the process works and the physics that sets its limits: osmotic pressure, recovery, salt rejection and membrane selection.
- Reverse Osmosis
A pressure-driven membrane separation process in which feed water is forced through a semi-permeable membrane, rejecting dissolved salts and producing a low-salinity permeate stream. The basis of modern seawater and brackish water desalination.
- RO System Recovery
The fraction of the RO feed flow that is recovered as permeate. Recovery is the primary control on concentrate flow, applied membrane concentration, and scaling risk, and is bounded by feed chemistry and membrane configuration.
- RO Salt Rejection
The percentage of dissolved solids retained by the RO membrane, computed from feed and permeate concentrations. Salt passage is its complement, and both are standard membrane performance metrics published per element.
- RO Membrane Selection
Choosing membrane and element families by feed salinity, target permeate quality, operating pressure window, and cleaning compatibility. Selection is driven by manufacturer projection data rather than single nominal ratings.
- Osmotic Pressure and Net Driving Pressure
The minimum pressure that must be exceeded on the feed side to overcome the osmotic pressure of the solution. Feed osmotic pressure determines the practical operating pressure floor of an RO train.
Hydraulics
Flow, head and pumping duty — including the high-pressure pump that dominates an RO plant’s energy and cost.
- High-Pressure Pumps in RO Systems
Pumps that pressurize RO feed water from the osmotic pressure floor up to the operating pressure required by the membrane train. Hydraulic power, efficiency, and energy recovery integration define system energy demand.
Sustainability
Whole-life considerations that sit alongside the process engineering.
- Embodied Carbon in Construction
The greenhouse-gas impact of producing and delivering construction materials (and, in wider boundaries, their whole life cycle). Embodied carbon is quantified by multiplying material quantities by emission factors and is a key lever when comparing design options.
Topic hubs
Wider engineering gateways. Each one explains the area, marks what the platform calculates against what it only describes, and links to the tools, technologies, demo cases and the plant designer.
- Desalination engineering
Process families, RO against thermal, seawater against brackish, and the couplings that decide the design.
- Pretreatment
Why pretreatment decides whether a membrane plant runs, and the barriers a train is built from.
- Mass balance, recovery and salt balance
Flow conservation, what recovery costs you, and why concentrate quality is an output rather than a choice.
- Membrane technologies
How UF, NF and RO differ by scale and driving pressure, and where each one sits in a train.
Guides and worked explanations
Longer treatments of one question, kept separate from the topic pages so each can go into the depth an engineer actually needs.
- Desalination Plant Designer: the complete design workflow
Why the twelve stages are ordered that way, and what each one is for.
- Desalination Plant Design Guide
The operator’s guide to the tool, with real captured screens and a worked Single-Stage RO example.
- Hydraulics System Design: From Flow to Pump Selection
How a stated flow becomes a duty point and a pump selection.
- Darcy-Weisbach and Hazen-Williams
Friction loss in pressure pipe and gravity pipe.
- Standard Rebar Weight Formulas
Bar mass per metre from section diameter.
- Embodied Carbon Screening: A Practical A vs B Method
Comparing two options on carbon before committing to one.