Water treatment belongs in the steam-system quotation from the beginning. Buying the boiler first and choosing treatment later can leave a gap between the equipment requirements and the water available on site. The useful starting point is a current laboratory analysis and a clear description of the operating duty.
Why the water specification matters
Hardness can lead to scale on heat-transfer surfaces. Dissolved gases can contribute to corrosion. Excess dissolved solids and other contaminants can affect steam quality through carryover. Treatment therefore addresses different problems; a single piece of equipment should not be assumed to solve all of them.
A conventional sodium ion-exchange softener removes hardness by exchanging ions, but it does not remove total dissolved solids in the way a demineralisation process does. The appropriate treatment train depends on the source water, boiler design, operating conditions and proportion of condensate returned. These principles are explained in Spirax Sarco: Water for the Boiler.
Prepare the information before requesting treatment equipment
- Identify the source: municipal supply, well, surface water or an existing treated-water system.
- Provide a dated laboratory report, including hardness, conductivity or dissolved solids, alkalinity, silica and other parameters requested by the treatment specialist.
- State normal and peak steam demand, operating pressure and working hours.
- Estimate condensate return and explain whether any process can contaminate it.
- Describe available water flow, storage, electrical supply, drainage and space.
Ask the boiler supplier for the feedwater and boiler-water limits for the exact model. Ask the treatment supplier to show how the proposed system meets those limits under your stated conditions. Do not substitute a generic internet dosing recipe or a limit taken from a different boiler.
Make supply responsibilities explicit
The quotation should identify each treatment stage, its rated duty and the assumptions behind that duty. Clarify whether storage, pumps, instruments, dosing equipment, consumables and installation are included. Request the expected service requirements, consumable availability and any waste stream that the site must handle.
Define sampling points and responsibilities for routine checks. Agree what happens when incoming water changes or returned condensate is unsuitable. Record who supplies the operating procedure, trains staff, interprets test results and adjusts the treatment programme. Operating limits and corrective actions should come from the agreed technical documentation.
Handover records to keep
Keep the source-water report, selected equipment data, commissioning results, approved operating limits, test schedule and service contacts together. Record water test results and consumable use in the plant log. A clear handover makes it easier to investigate changes in operation without guessing which assumptions were used at purchase.
For a new project, include water treatment in the steam boiler quotation checklist. If evaluating a compact unit, read the steam generator selection guide as well. Send the water analysis with your enquiry so the proposed boiler and treatment scope can be reviewed together.
