Ask a plant manager how the housing got clean and the answer is usually a name and a shrug: the late shift did it again. Ask what was actually done and nobody can say, because between shifts the work is squeezed into the break in production, done by whoever is free, and judged by eye. A service provider who wants that housing to come back clean on every shift does not need more diligence. They need the method written down in a form that survives a handover, a rota and a new starter.
Write the housing down as an asset, not as a spot
Documentation starts before the cleaning method. One line per housing in the register: which machine it belongs to, what it encloses, what it is made of and how it is finished, how it is opened and closed, where the run-off goes, and what has to be protected or masked before anything wet touches it. Gearbox housings are not one surface. A cast cover with machined mating faces behaves differently from a fabricated and painted sheet-steel cover, and a cover with a breather, a sight glass or a sensor cable running through it has openings that decide the whole method.
Record the soil in the same entry, in plain words: way oil and cutting fluid thrown off in operation, graphite and abrasive fines from the gears, chain or guide lubricant, road or yard grit at the lower edges, whatever leaked from a seal and got coated with dust. Soil type sets dwell time and heat; it does not belong in a general instruction that says "clean the housing".
Fix the shift window, because the window is the constraint
Between-shift work is short, so the document must state the working window in minutes and then design the method to fit it. Write down when the window opens, when the line is expected to restart, and who decides if the job runs over. Then state, for each housing, what one operator can complete inside that window without running ahead of the restart. Those minutes are also what a buyer needs before anything is quoted: send the supplier the window length, the number of housings per shift and the soil you are fighting, and ask them to state the time per housing for the mode they recommend. Where the housing cannot be finished in the window, the document should say so and split it: a light maintenance pass every shift, a deeper descaling pass on the weekend or during planned maintenance. Writing "clean it properly" with no clock attached is how housings end up half done, and how the estimate that follows turns out to be wrong.
State the method in the order it happens
A usable instruction reads as a sequence anyone can follow without asking. For an external housing the usual order is: isolate and prove the machine is stopped and cannot start; let surfaces cool to a temperature that can be worked on; clear loose dry soil without creating airborne dust; mask or cover breathers, shaft ends, sensor connectors, cable glands, bearing vents and any gap that leads inside; pre-heat to soften the set deposit and leave it to dwell rather than scrubbing at it; work from the top surface downwards so released soil runs onto surfaces still to be cleaned; collect the run-off as it is released; wipe or squeegee dry; remove the protection; close up and hand back to production with the covers and fasteners counted back.
Say which medium and mode, not just "steam". A fixed steam cleaning machine with selectable dry and wet steam lets the operator use the drier mode to soften heavy deposit with long dwell and little water, then the wetter mode to lift what has released, then finish dry. That sequence is what makes an in-shift pass repeatable in a short window; an instruction that only names the machine leaves every operator to invent their own order.
Put the equipment facts on the card, with what is unknown
Attach the equipment specification the supplier publishes, so the person writing the shift routine is not guessing at capability. For the PowerDe HW02 listed on the cleaning equipment pages, the detail page states 220 V working voltage, 6 kW heating power, 160 degrees C steam temperature, 0.8 MPa vapour pressure, an 80 L SUS304 tank, tap-water inlet with a 1/2 inch four-point internal-tooth joint, dry and wet steam plus a vacuum cleaner, and overall dimensions of 1,200 by 800 by 1,200 mm including handles. Note what the page does not give, and require it from the supplier in writing before the routine is signed: continuous working time per tank fill, water consumption per hour, hose and lance length, the accessory set, machine weight and how it moves between machines, and the protection features listed for the unit.
Then write the local checks against that equipment: the supply socket and its circuit, where the tap water connects, whether the fitting matches at that point, how far the machine has to be moved between housings, and where the run-off may legally go. Half of the failed in-shift jobs are not cleaning failures; they are a machine that could not be fed, or water with nowhere to go.
Define "clean" so two shifts agree
Write the pass criteria the way a verifier will apply them, and keep them short enough that they get used. For a housing exterior that normally means: no soft film or slurry left standing in corners, ribs and bolt pockets; no fresh oil tracking from a seal line once wiped; machined faces and fastener heads free of built-up grime; breathers and vents free of the dust cap that forms around them; sight glasses readable; no run-off pooled in a ledge or a drip tray left behind; and no residual heat or damp at electrical entries after the protection is removed. Photograph one known-good housing and one known-bad housing and put both images on the card. Verbal standards drift within a rota; photographs do not.
Name the hazards the housing creates
The document has to carry the safety conditions or it will be treated as a suggestion. For this job: lock-off and tag before touching anything, because a housing looks harmless and a machine does not; a hot surface plus steam plus water is a burn route, so gloves, sleeves and eye protection are part of the method rather than a reminder; directing a jet at a seal, a bearing vent, a cable gland or a gap drives contamination and water into the bearing the cleaning was meant to protect, so the instruction must name what must never be sprayed; and run-off on the floor under a machine is a slip hazard for the next shift, so the collection and drying step is written into the sequence and signed off.
State who is allowed to start the job. A shift handover is not a training record. Anyone signing the card should be able to show they have read the method, the hazards and the pass criteria for that specific housing.
Keep a record that answers the audit without a memory test
One line per pass: date, shift, housing identifier, operator, machine and mode used, start and finish time, pass or fail against the photographs, anything that had to be re-worked, and any defect noticed but not fixed - a weeping seal, a chipped coating, a missing breather cap, a bolt pocket that keeps collecting. That last column is the value of the record. The housing tells you which seal is failing before the bearing does, and only if somebody wrote it down.
| Field on the card | Why it is there |
|---|---|
| Housing identifier and machine | So the pass is attributable to an asset, not to an area |
| Shift, operator, start and finish | Shows the job fits the window and who did it |
| Machine, mode, dwell used | Turns the method into something a new operator can copy |
| Pass criteria result | Replaces "looks fine" with an agreed standard |
| Defect and rework noted | Feeds maintenance instead of disappearing at handover |
Review the paper, not only the housing
Frequency belongs to condition, so review the record monthly rather than trusting the calendar. Any housing that fails twice in a month gets its window, its dwell or its frequency changed, and the change goes onto the card with the reason. Any method the crew quietly modified - a longer dwell, a different mode, a masking step they invented - is a gap in the document, and the fix is to write their version in, not to argue about it.
A supplier who takes this seriously will ask for the housing details before quoting, and will answer with a recommended dwell, standoff and mode for your soil rather than a brochure. Send the register to the team behind the customized cleaning solutions, in writing, with photographs of the worst housing and the record of what your current method achieves. That is how you find out what the equipment is actually cleared for.
Run one shift against the written method, with somebody recording where the operator had to improvise. Those improvisations are the missing lines. Write them in, and the next shift hands over a documented process instead of a habit.
