Every plant says it tracks water, yet most cleaning stations are the one line item nobody can price. The plant meter shows a monthly total, the maintenance team rinses machines with a hose at the end of each shift, and no one can say which activity produced which part of the bill. Before any cleaning method is changed, the question worth answering is narrower: how much water does one cleaning task actually consume, and what is the cost of the water plus what sits around it?
1. Measure the task, not the meter
A plant-level water bill cannot separate machine cleaning from cooling make-up, restrooms, or cafeteria use. So start at the task. Choose two or three representative cleaning jobs — a machining centre wipe-down, a conveyor degrease, a floor wash around one machine — and record what each one actually uses.
Three methods, in rough order of reliability:
- A flow meter on the cleaning hose or the wash-bay supply line, read before and after the task. This gives litres per task directly and is the only number you can defend in a meeting.
- A timed run on a known flow rate: note the nozzle or gun flow, multiply by trigger time. Less accurate, but enough to compare two methods on the same machine.
- A count of passes or buckets per task, used when no metering exists. Crude, but it exposes how much of the cleaning is habit rather than need.
Do the measurement on the current method, not the proposed one. You need a baseline, and the baseline is also what tells you whether the alternative is worth buying.
2. Price what the water leaves behind
Water that leaves a machine tool is not clean water. It carries cutting-oil residue, way grease, swarf fines, and any detergent that was added to speed the job. In most plants that runoff goes to an oil-water separator or a wastewater treatment line, and both carry running cost: separator consumables, sludge handling, treatment chemicals, periodic disposal.
Ask the treatment contractor or read the internal discharge log for two things: the volume going to treatment from the cleaning area, and the contaminant load the separator is dealing with. Both move in the same direction as water volume, which is where cleaning method becomes a cost question rather than a housekeeping question. A method that uses less water and needs no detergent usually lowers both lines at once.
There is a second, quieter cost: downtime. A machine cleaned with flooded water and detergent needs drying time, and water reaching ways, ball screws, or electrical enclosures invites rust and later repair. Cleaning time per machine, per shift, multiplied by the machine's hourly output value, is frequently larger than the water bill itself.
3. Compare methods on the same task list
Put the options side by side against the tasks you measured, not against a specification sheet. The usual candidates in a machine shop are a manual hose-and-brush routine, a pressure washer, a solvent or detergent wipe, and a machine tool steam cleaning unit.
For each option, record the same four columns: water used per task, labour minutes per task, chemicals consumed per task, and whether the machine can return to production immediately. Steam looks weak on the first pass only if you compare equipment cost. On the four measured columns it usually wins precisely on the two that cost the most: labour minutes and return-to-production time. Dry steam, at 160°C and around 0.8 MPa on the PowerDe HW02 steam cleaner, lifts hardened cutting fluid and way grease with a small volume of water, and the surface leaves nearly dry, so there is no drying wait and no standing water near ways or enclosures.
Run the comparison as a pilot on one machine for two weeks with the meters in place. Two weeks of real numbers beats any vendor claim, and it gives the maintenance team a reason to accept the change.
4. Check the equipment against the shop floor
Numbers that look right on paper fail on the floor for predictable reasons. Before specifying a unit, confirm these items against your own layout:
- Water source and tank size. A fixed unit fed from tap water runs longer between refills; the HW02 carries an 80 L SUS304 tank with a tap-water inlet, which sets how many machines one operator can finish.
- Electrical supply. A 6 kW heater on a 220 V supply needs the right circuit available where the cleaning actually happens, not only in the utility room.
- Reach. Hose and wand length decide whether the unit follows the machine or the machine waits for the unit. Measure the distance from the power point to the farthest machine in the bay.
- Protection. Cleaning around electrical enclosures demands leakage, short-circuit, high-temperature, and water-shortage protection, plus an operator who has been trained on nozzle distance.
- Mobility versus position. A fixed unit suits a defined wash bay; a hand-pushed or driving-style unit suits shops where cleaning follows the machines between shifts.
Where the fit is not obvious, intelligent cleaning equipment manufacturer PowerDe works from your task list and shop layout rather than pushing a single model, and the cleaning equipment series covers fixed, hand-pushed, and driving-style configurations.
5. Write the number into the maintenance standard
The evaluation only holds if it becomes a standard. Fix the cleaning method per machine, record water litres and labour minutes per task in the maintenance sheet, and re-measure after a month. Two things normally show up: some tasks were being over-cleaned, and one or two tasks — usually conveyor degreasing or the chip conveyor area — were the real water consumers all along.
Once the tasks are separated and priced, the decision stops being about water. It becomes a comparison of labour minutes, downtime, chemical use, and treatment load, which is the comparison most plants lose with a hose and a brush.
