Gate one: name the surface before you name the machine
The first written answer is a list, not a specification. Walk the line and write every face you intend to put steam against: the flat tops, the splashing backsplash, the undershelf where drips have cured, the frame around an oven door, the handle, the hinge, the latch, the underside of a removable panel. A cooking line is not one surface. It is five or six materials that behave differently, and a purchase decision made against the phrase "the line" will be judged later against the worst face on it.
Write the deposit next to each face, and write how old it is. A film wiped yesterday and a carbon deposit that has survived three cleaning cycles are different problems that happen to sit on the same metal. A buyer who cannot separate them cannot read a demonstration, because the demonstration will be run on whichever one flattered the equipment.
Gate two: write down what must stay untouched
Before anyone discusses capability, list the parts on that line that no one in your building is authorised to open, remove or spray. On most cooking equipment that includes the burner assembly and its gas train, the electrical enclosure behind a control panel, the fan section of the extraction run, and the insulated cavity behind a panel. Those exclusions shrink the job. They also decide what size and shape of equipment you need, because a machine bought for the open faces has to be usable without leaning over a guarded area.
Ask the equipment maker, in writing, which openings and components their own instructions exclude, and compare that with your list. Where the two lists disagree, the disagreement is a finding, not a detail. It is the part of the job a supplier's recommendation will quietly route around.
Gate three: judge the equipment against the room, not the catalogue
Cooking lines are tight. A buyer should walk the assessment against the physical facts of the space: where the machine will sit, whether it has to be moved past a service counter or through a door that is normally held open by a trolley, how far the working hose reaches from a fixed position, whether there is a water connection and a drain near the task, and where the run-off goes. Run-off is a decision, not an accident. Grease-laden water leaving a cooking line has to arrive at a named receiving point, and if no one has named one, the purchase has an owner-less cost attached to it.
A supplier page that shows a unit working in a yard, a pit, or a vehicle bay tells you about that scenario. It does not tell you about yours. The central kitchen degreasing entry on this site points at a fixed machine listed for vehicle and yard work; the listing carries no claim about a cooking line, and a buyer who reads it as one will be carrying that risk onto their own floor.
Gate four: read a supplier document as a set of claims to test
Most assessment work fails here. A supplier sends a sheet of numbers and the buyer reads it as a specification of their own job. A quoted figure describes a machine under its own test arrangement. It does not describe your surface, your deposit, your water, your shift pattern, or your access. Keep the figures where they belong - as claims about the equipment - and put each one in the same column as the question that tests it: what happens on a vertical face, what happens on a horizontal one, what happens at the underside of a shelf where the nozzle cannot point straight down.
Ask which of those questions the supplier has actually seen answered, and where. If the answer is a demonstration on the supplier's own panel, note that. Then ask for the same panel result expressed as a condition you can check: not "clean", but the visible residue you expect to see removed, on a marked square of your own equipment.
Gate five: run the bounded trial and describe the result before you start
This gate is the only compatibility proof, and it should be small and pre-written. Choose two faces your team actually works: one horizontal, one vertical. Mark a patch on each. Write what you will accept - the deposit removed to the metal, no residue left at a weld root, no damage to a finish, the surface dry and back in service inside the window you can spare. Write the stop condition before the first pass, so the trial cannot quietly turn into a demonstration.
Record three things during the trial: the time the task took end to end including set-up, the water and run-off the task produced, and what your operator had to do that the written method did not mention. Those three lines are worth more than any catalogue. If the trial is run at the supplier's premises on their panel, it proves transportability, not fit.
Where the two halves of the market differ
A portable unit is judged by whether it can be carried to the face and used from where the operator stands. A fixed installation is judged by whether the faces can be reached from one position, whether the drainage from that position is acceptable, and who owns the station afterwards. Neither is cheaper in the abstract; the difference shows up in how many operator steps each one removes on your particular line, which is a fact only your trial produces.
If a line has faces that no stock arrangement reaches cleanly - a narrow cavity, a deep splash-back, an awkward underside - that is a build-to-order question rather than a rejection, and it is worth putting to the supplier in writing before the commercial conversation starts. Sites that build to order will ask for the drawing and the deposit description; the customized steam cleaning enquiry route on this site is where that description goes.
A short list of failure signals, and the gate each one points to
A result that looked excellent in the demonstration and poor in service usually came from gate one: the deposit was never written down, so the trial tested the wrong problem. A machine that works but never gets used usually came from gate three: the room was never assessed, and the operator cannot get it into position without a second pair of hands. Damage to a component came from gate two: the exclusion list was never agreed. A figure that "did not work" came from gate four: a claim about someone else's test arrangement was read as a promise about your floor. A clean surface that fails the next inspection came from gate five: the finish was never written as a checkable condition. None of these are faults of the steam itself; they are gates skipped, and a skipped gate is visible in the paper trail long before it is visible on the equipment.
Assessment of PowerDe cleaning equipment, like any other, ends at the same place: a written surface list, a written exclusion list, a written result description and a bounded trial on your own faces. Order the paperwork before the machinery and the decision becomes a comparison rather than a guess.
