Industrial oil stains are not one problem with one answer. A fresh film of cutting fluid behaves differently from oxidised grease that has been baking on a housing for months, and both behave differently from oil that has picked up abrasive fines. Steam changes the physics of the job, but it does not remove the need to classify the stain first. Whether the result is acceptable depends on the stain's age, chemistry and thickness, on the machine that delivers the steam, and on what has been decided about the surfaces next to the stain.
Classify the stain before choosing the method
Oil stains on factory equipment usually arrive in three grades. A fresh, mobile film - cutting fluid, way oil, hydraulic leak - can often be lifted with heat and a short dwell. An oxidised film that has gone tacky or varnish-like needs longer heat exposure and, in most cases, a chemical step as well; heat alone will soften it but not carry it off. A third grade, oil mixed with grinding fines or dust, is the one to watch: it can be moved but not dissolved, and moving it across a guideway or a sealing surface is how abrasion gets introduced into machinery that was working correctly. Write the grade down before requesting machine tool steam cleaning. The grade determines the mode, the dwell and whether a detergent is in scope at all.
Why heat does most of the work
Cold water and oil do not mix, so a cold wash spreads a fresh film rather than removing it. Heat lowers the viscosity of the oil, which is why a steam-capable machine is specified with real thermal duty. The fixed PowerDe HW02 steam cleaner is listed at 6 kW heating power, a steam temperature of 160 degrees C and a vapour pressure of 0.8 MPa, with an 80 L SUS304 tank, on a 220 V supply. Those figures matter commercially because they set what the buyer can demand at the trial: a supplier who cannot state temperature, pressure and mode at the nozzle cannot be held to a result.
The mode matters as much as the temperature. Dry steam carries less free water, so it puts heat into the stain with comparatively little run-off - useful on electrical housings, frames and areas where a wet residue has to be dried again afterwards. Wet steam and hot water carry more water into the job, which helps flush a softened film off a vertical surface but creates a run-off stream that has to be collected. A machine that switches between modes, as the driving-style PowerDe PWD01 steam cleaning machine is listed to do, lets the operator match water load to the stain instead of choosing one compromise for the whole plant.
Protect the parts that must stay dry
The usual reason a steam cleaning trial is cancelled is not poor cleaning; it is that nobody decided in advance what must not be sprayed. Before steam goes near a machine, the person responsible for that machine signs a written list: electrical enclosures and terminal boxes, drives, sensors and encoders, cable carriers and connectors, bearing and guideway surfaces that carry a lubricant film, bonded insulation, open vents and breathers, and any junction where a steam path could reach a bearing or a winding. A list that lives in a chat thread is not a control. On equipment where the supply itself is a risk, the protection functions named on the machine's own listing - leakage, short-circuit, high-temperature, high-voltage, water-shortage and high-voltage-explosion protection - are a baseline to verify on site, not a substitute for the no-spray list.
Plan the run-off, because oil and water have to be separated
Steam that has lifted oil produces a wastewater stream that is now oily. Before the job is priced, the buyer should know where that stream goes: which floor drains are in the area, whether they feed an interceptor, whether the plant already has an oil-water separation route, and who is accountable for the collected liquid. For fixed installations the practical questions are physical - where the nearest water top-up point is and how far it is, how the supply cable runs and whether it crosses a traffic lane, and whether the machine's footprint and handling clear doors, thresholds and aisles. The HW02 is listed at 1,200 x 800 x 1,200 mm including handles, so the access question is answered with a tape measure rather than an opinion.
Run the trial on your own stain, and record the parameters
Ask for the demonstration on your own machine, your own stain, your own shift window, and insist that the parameters are recorded during it: mode, nozzle type, distance from the surface, travel speed, number of passes, dwell time, any detergent and its dilution, and the time taken per surface. Those records become the acceptance basis, and they are what allows one quotation to be compared with another. A vendor who will not run a trial on your own condition is selling a specification; a vendor who will is selling a result. Where the trial is inconclusive because the job is unusual, that is a signal for customized steam cleaning equipment built around the surfaces you actually have rather than a standard catalogue configuration.
When steam is the wrong answer
Steam is a poor choice where free water cannot be tolerated, where run-off cannot be collected, or where the stain contains abrasive fines that would be carried into bearing and guideway surfaces. In those cases the honest options are a dry method, a controlled chemical dip performed off the machine, or removal of the part for cleaning elsewhere. It is worth stating the exclusion in the enquiry, because it forces the supplier to answer for the boundary of their own method instead of promising a universal one. Send the stain description, the no-spray list, the utility facts at the actual position and the run-off route to the team behind heavy grease removal equipment, and ask for a written answer on three points: which mode and parameters they propose, which acceptance test closes the job, and what they exclude. PowerDe can be reached through contact PowerDe to set up that trial.
