- Compare boiler chemical quotes as Rs per tonne of steam, not Rs per kg of chemical
- Include testing and service visits, which can change the ranking
- Total cost per tonne = chemical cost + service and testing cost
- Every figure here is an illustrative input, not a Seamens price
Boiler chemical quotes are often compared on price per kilogram, even though a concentrated product and a dilute product are used in very different quantities. The fair comparison is cost per tonne of steam, with testing and service visits counted in. This guide shows the method, a worked example and a free calculator.
Why compare boiler chemicals per tonne of steam?
Cost per tonne of steam puts every programme on the same footing, because it divides what you spend by what the boiler produces. It makes a high-dose, low-price product and a low-dose, high-price product directly comparable, and it shows whether service visits are worth their cost.
How do you calculate chemical cost per tonne of steam?
Chemical cost per tonne of steam equals daily chemical use in kilograms multiplied by price per kilogram, divided by tonnes of steam produced per day. Steam per day equals steam output in tonnes per hour multiplied by operating hours.
Formulas: steam per day = tonne/h x hours; chemical cost per tonne = (kg per day x Rs/kg) / steam per day; service per tonne = monthly service cost / (steam per day x 30).
What does a worked example look like?
The figures below are illustrative inputs for a 5 tonne/h boiler running 20 hours a day. They are not Seamens prices.
| Step | Programme A | Programme B |
|---|---|---|
| Chemical used per day | 12 kg | 8 kg |
| Price per kg | Rs 400 | Rs 550 |
| Chemical cost per day | Rs 4,800 | Rs 4,400 |
| Steam per day (5 t/h x 20 h) | 100 tonnes | 100 tonnes |
| Chemical cost per tonne | Rs 48 | Rs 44 |
| Service and testing per month | Rs 30,000 | Rs 30,000 |
| Service per tonne (30,000 / 3,000 t) | Rs 10 | Rs 10 |
| Total per tonne of steam | Rs 58 | Rs 54 |
Programme B costs more per kilogram but about 7% less per tonne of steam in this example. Try your own figures below.
What does the per-tonne figure not include?
The per-tonne figure covers chemicals and service only. Fuel lost through blowdown, scale on tubes and downtime are separate costs that a good programme reduces, so track them alongside the chemical cost.
- Blowdown losses: heated water discarded to control TDS. See the boiler blowdown calculator.
- Feed water quality: higher TDS means more blowdown. See Lahore groundwater TDS and what it means for boilers.
- Scale and fuel use: deposits on tubes raise fuel consumption.
- Downtime: an outage costs far more than a month of chemicals.
What should a boiler chemical quote contain so you can calculate this?
A quote should state the daily dose, the product and price, the testing routine, the visit schedule and any response commitment. Without a daily dose, you cannot convert the price into a cost per tonne of steam.
| Quote item | Why you need it |
|---|---|
| Daily or hourly dose for your boiler | Converts price into daily cost |
| Water analysis the dose is based on | Shows the dose is designed for your water |
| Testing routine and limits | Defines how the programme is controlled |
| Service visits and reports | Gives the service cost to include |
| Response time for out-of-range readings | Defines the support you are buying |
Seamens Enterprises supplies the Water Safe Boiler Treatment programme, which provides oxygen scavenging, scale inhibition, pH conditioning and sludge dispersal for fire-tube and water-tube boilers, with on-site analysis and monitoring visits. Read how to choose a reliable boiler chemical supplier in Lahore.