Equipment selection and datasheets — choosing each unit on duty, materials and lifecycle cost, and specifying it for procurement.
Process Design & P&IDs — in depth
Process design culminates in equipment selection. Each item — pumps, blowers, mixers, screens, dosing — is chosen on duty point, materials, efficiency and whole-life cost, then captured on a datasheet that defines the procurement specification, so what is bought matches what was designed.
What matters in practice
Flow, head and load define the selection.
Matched to fluid and environment.
Energy and lifecycle cost considered.
Procurement-ready specifications.
| Field | Purpose | Note |
|---|---|---|
| Duty | Sizing | Flow/head/load |
| Material | Durability | Spec |
| Power | Energy | Efficiency |
| Standards | Compliance | Codes |
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A companion deep-dive in this series.
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Read MoreA companion deep-dive in this series.
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Read MoreThe wider hub for this subject area.
Read MoreReynolds & Bauhm designs and delivers process design & p&ids solutions backed by process engineering and performance guarantees.
Fundamentals, design drivers and practical guidance
Equipment selection and datasheets — choosing each unit on duty, materials and lifecycle cost, and specifying it for procurement.
The hydraulic profile sets the elevations so water flows through the works against friction and unit head losses with adequate freeboard, minimising intermediate pumping; the P&IDs then formalise instrumentation, control philosophy, interlocks and safety. Equipment selection weighs capital against operating cost, robustness, turndown and maintainability — choosing technology that suits the operator's site and skills, not just the lowest tender.
Reynolds & Bauhm develops plant designs from a rigorous mass balance through hydraulic profile, P&IDs and equipment selection, so the works is sized for its true duty, flows correctly, and is specified for whole-life cost and operability.
Process plant design turns an effluent characterisation and a discharge consent into a buildable, operable works, and it proceeds through recognisable deliverables: mass balance, hydraulic profile, P&ID development and equipment selection. Each builds on the last — the mass balance sizes the duties, the hydraulic profile makes them flow by gravity where possible, the P&IDs capture control and safety, and equipment selection commits the technology.
What our engineers assess on every scope of this type
| Parameter | Typical basis | Why it matters |
|---|---|---|
| Turndown | Range of duty | Handles diurnal/seasonal swing |
| Operability | Suited to operator | Keeps the plant runnable |
| Mass balance | Flows + loads tracked | Sizes every unit to real duty |
| Hydraulic profile | Elevations + losses | Flow by gravity where possible |
| P&IDs | Control + interlocks | Formalises operation and safety |
| Equipment | Whole-life basis | Balances capex and opex |
Common questions on treatment plant design
P&IDs formalise the control philosophy, instrumentation, interlocks and safety functions. They are the reference that procurement, commissioning and operations all work from, so getting them right early prevents rework.
On whole-life cost, robustness, turndown and maintainability — matched to the operator's site and skills — not simply the lowest capital tender. The cheapest item often costs the most to run.
Real plants see diurnal and seasonal swings in flow and load. Designing for turndown, with appropriate redundancy, keeps treatment stable and efficient across the full operating range, not just at average duty.
Because it sizes everything — flows and loads through each unit, including solids and recycles. Equipment Selection & Datasheets and every downstream deliverable depend on a correct balance, so it is built and checked first.
Our expertise spans multiple industries with sector-specific water treatment solutions.
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