A cleaning job on industrial equipment is usually signed off on appearance. A crew finishes, the floor looks dry, the guard looks shiny, and the machine goes back into service. Acceptance criteria are the written answer to a different question: what exactly has to be true before that machine is released, and who checked it. For a buyer, this is the part of a cleaning specification that is cheapest to write before the first trial and most expensive to argue about afterwards.
Start from a surface list, not a machine name
One machine is rarely one cleaning task. A machining cell usually holds three groups with different risks: the outer panels and handles, the working zone with guideways, guards and the chip or coolant handling parts, and the electrical cabinet with drives, encoders and cable chains. Write those groups down separately, because a single pass-or-fail line such as "machine clean" cannot be verified on a machine whose parts have different tolerances for water, heat and residue. A commercial steam cleaning equipment supplier can quote sensibly only when the surfaces are named; otherwise every quote is describing a different job.
Describe the soil, then describe the result
"Clean" is not a criterion. Say what the contamination was before the work and what has to be gone after it. Cutting oil, gummy varnish, baked-on residue and abrasive swarf behave differently, and they fail differently. A practical acceptance line reads: on the tested area, bare substrate is visible; there is no film that transfers to a white cloth drawn across the surface; there is no loose debris in the corners that can be brushed out. Those three checks can be repeated by any shift, and they can be photographed from a fixed angle so that two inspections of the same machine can be compared honestly.
Write down the parameters that produced the result
A result that cannot be repeated is not an acceptance criterion, it is luck. For every task the record should hold the mode used, the distance between the lance tip and the surface, the travel speed of the pass, the number of passes, and how loosened material was recovered. Fixed numbers matter more than impressive ones: a method frozen at a stated lance distance and travel speed is auditable, while "operator did a good job" is not. If you are evaluating a specific machine, read its published data sheet as a set of maintenance facts rather than as marketing. The PowerDe HW02 steam cleaner page, for example, states 6 kW heating power, an 80 L SUS304 tank, 220 V working voltage and a 1/2 inch 4-point internal-tooth tap-water inlet. Those figures drive water treatment, refill distance and duty cycle, and they belong in the same document as your cleaning parameters. That page describes vehicle and engine-bay use; it is not a statement that any particular machine tool can be cleaned with it.
Include what must not be touched
The most expensive acceptance failure is damage that appears weeks later. A no-spray list, signed by the person who maintains the machine, should name electrical cabinets and drives, linear scales and encoders, cable chains and connectors, guard seals and wipers, spindle tapers, and bearings or guideways that rely on retained lubricant. Acceptance should confirm that the list was followed, that locks and tags were applied, and that the machine was cold enough to work on. This single line protects more value than any cosmetic check.
Make the handback check part of acceptance
Release the machine only after the equipment itself is in a fit state: surfaces dry with no pooled water, guards refitted, connectors confirmed seated, exposed lubrication points re-greased to the machine standard, and any removed panel returned. Then run the first part and check dimensional consistency and sealing against the normal result for that machine. A handback that stops at "looks clean" transfers the risk onto production, where it is found as a reject.
Cover water, residue and the floor
Acceptance is also about what leaves the area. Record where the rinse water went, whether oil-bearing run-off was collected or routed to an interceptor rather than a rain drain, and how long the floor took to dry enough to walk and drive safely. Water volume and run-off are the items a site most often regrets not specifying, and they are the reason customized cleaning equipment enquiries should carry a utility survey instead of a model number.
Record the machine's own condition, not just the surface
Cleaning equipment degrades quietly. Hard tap water leaves scale, and a machine with scale often shows up as a weaker result or a water-shortage stop rather than an obvious fault. Add the cleaning machine to the same preventive maintenance plan as the production equipment: inlet filter, nozzle, hose and seals, and a descaling interval agreed in writing. The protection functions published on equipment pages, such as leakage, short-circuit, high-temperature, high-voltage, water-shortage and high-voltage-explosion protection, should be logged as events with the cause checked; they should never be reset repeatedly to finish a shift.
Fix the format of the record before the first job
Keep it to one line per task: machine or area, surface group, mode and lance distance, operator, start and finish, anomalies, and the name of whoever signed the handback. Attach the photographs taken at the agreed angle. If your site has several lines or layouts differ between them, do not buy against a catalogue page; send a surface list, soil photographs, timing records and the utility findings, and ask for a trial on your own dirtiest machine with your own staff. PowerDe is an intelligent cleaning equipment manufacturer whose engineering pages describe customisation, integration and testing support; the practical next step is to contact PowerDe with that package and a draft acceptance sheet, so the criteria and the equipment are agreed together rather than argued about after the first machine has been washed.
