Wet steam is not one setting but a balance of steam temperature, moisture content, feed water, and dwell time. Buyers should request that these values be written down for each mode, together with the conditions under which they were measured. The same machine can behave very differently in a heated indoor bay and in an unsheltered parking area.
What the term actually describes
Dry steam leaves the lance as a low-moisture vapour and works mainly through heat. Wet steam carries more liquid water, which adds mechanical flushing and shortens the time a surface needs to be held hot. Many commercial steam cleaning equipment units, including the driving-style PWD01 and PWD02 models, list dry-steam, wet-steam and hot-water modes, so the practical question is where the boundaries between those modes sit and what they cost in water and energy.
Questions to put in the RFQ
- Boiler or heater output in kilowatts, and whether the rated steam temperature and pressure apply to wet steam or only to dry steam
- Water tank volume, inlet water requirements, and how long the unit runs on one fill in wet-steam mode
- Whether wet-steam mode is available on battery power, and for how long, or whether the mode requires a mains supply
- Warm-up time from cold start, and how quickly the machine recovers after the lance is held open continuously
- Which protections stop the mode when the tank runs low, and what happens to the work in progress
- Whether the steam hose and lance supplied are rated for the wet-steam moisture level, and what their lengths are
Fixed units such as the high-pressure steam cleaning machine HW02 show how much headroom a stationary installation can provide: 6 kW of heating power, 160 °C steam temperature and 0.8 MPa vapour pressure, fed from an 80 L tank. A battery-powered mobile machine in the same product family will trade part of that capacity for range, which is why mode-specific figures matter more than the model name.
Where wet steam runs into limits
Water is the first constraint. Wet-steam mode consumes more feed water per minute than dry steam, so a small tank sets the working rhythm: fill, clean, refill. In a car park or garage without a nearby tap, that rhythm decides how many vehicles one operator can finish.
Electrical supply is the second. Continuous wet steam at high output draws steady power, and on battery models the runtime of that mode can be shorter than the runtime of dry steam. Ask for the figures per mode rather than one averaged number, and check whether the site electrical supply matches the machine's working voltage.
Drainage and surface type are the third. Extra liquid water means runoff that has to leave the working area, which rules out some indoor floors and upper-level bays unless drainage exists. Heat-sensitive parts, painted surfaces and open electrical enclosures also need a lower-moisture setting, so confirm that the mode can be stepped down instead of being all or nothing.
Testing the mode before the order
Ask the supplier for a trial on your own soiling, not a demonstration on a clean panel. Run the lance continuously for the length of a typical job and record tank level, recovery time and any interruption. For engine work, review engine compartment steam cleaning notes on the product page and bring the same connectors, covers and shielding you use in daily service.
A buyer who leaves the meeting with measured figures per mode, a stated water and power requirement, and a drainage plan for the site will compare machines on the same basis instead of on marketing descriptions. PowerDe's engineering services pages cover customization and hardware testing for buyers whose site conditions fall outside the standard configurations.
