Why the interior of a feed tanker is its own inspection object
A tanker that has carried meal, pellets or cracked grain is not a dirty drum. The residue it leaves is a mixture: fine dry dust worked into weld seams, a fatty film from any molasses or oil coating that was sprayed onto the ration, damp paste where condensation met the cone, and crust packed behind fittings that nothing reaches during discharge. A load of the next commodity moves across all of it on the way out, so the condition of the interior is part of the load, not a separate housekeeping matter. That is why an assessment has to be carried out on the surface itself rather than on the visible part of the shell.
This is also where a buyer should read the catalogue honestly. The cleaning machines listed on PowerDe cleaning equipment are positioned on those pages around vehicles, parking facilities and medical equipment, and the same is true of the PowerDe PWD01 steam cleaner. Nothing on those pages says the machine is qualified for a feed tanker or for any farm or feed duty. The cleaning programme below is therefore the fleet owner's own job: your surface list, your acceptance standard, your trial and your permissions. The supplier's role is to answer questions about a particular unit and, where the job genuinely needs something built for it, to take on the build through customized steam cleaning equipment.
Walk the inside before you write anything down
Do the walk with the tank empty and, if it can be done safely at your site, with someone able to watch the person entering. Use the words your own crews use for each part, because the finished assessment becomes a working document at the wash point and not a specification in a folder. For each row record four columns: the surface, what is normally found on it, its material and condition, and whether a person or a lance can actually reach it while standing where they will have to stand.
A typical interior list runs to more rows than most people expect. The cylindrical wall, top and bottom of the arc. The two end walls and the weld line where they close. Longitudinal seams and circumferential seams, including any backing strip on the inside. The discharge cone and its hopper. The internal ribs, brackets or breaking lugs if the tank has them. The manhole or top hatch with its seal groove, clamps and the underside of the lid. The discharge door, slide or valve with its seat, guide channels and any packing. The internal pipework, ladder rungs, wear plates and bolts. The outside of the shell is a different list with different risks and should not be folded into this one.
Type the deposit row by row, because the deposit decides the method
Feed residue is not one thing. Loose dry dust comes off with air and brushing. Damp paste that has dried against a cold wall needs time and mechanical lifting. A film from coated or molasses-treated feed is sticky, attracts dust, and is the layer most likely to be left behind by a rinse that looks clear. Where moisture has sat for days against a seam, the assessment should say plainly that a film may be present in a form no visible check settles, and that the answer for that row is either removal and inspection, or a written decision about what the next load is allowed to touch.
This row-by-row typing is the difference between an assessment and a wish list. A single word such as "degrease the tank" gives a crew nothing to hold somebody to, and it hides the cost, because a method that floods a cone is cheap to describe and expensive to run. For each deposit type, the assessment should state the tool or method, how long the method is allowed to keep that row wet, and what has to be true afterwards before the tank is closed again.
The fittings, seals and surfaces that must not be washed without a decision
Any competent assessment has an exclusion column, and for a tanker that column is long. Door and hatch seals and their grooves, unless the parts are listed as cleanable and replacements are on site. Bearing surfaces, the spindle of a slide or screw mechanism, and any lubricated linkage, because washing drives out what keeps them moving. Electrical enclosures, cable entries and lighting on the vehicle. Nameplates, hazard markings and any printed or painted identification. Coated or painted interiors of unknown history, including anything previously re-coated. Where a row is excluded, the assessment must name the replacement method and the trade you accept for it, for example wiping and re-inspection in place of a wet pass, and it must say who signs that decision.
A caution worth writing into the document: heat and dwell are not a licence. A method that lifts a film and leaves the film has moved the problem somewhere else, so every wet row on the list needs a lift step and a dry step. A vapour or rinse that softens residue in a seam and is then left to dry in that seam has produced a different residue, not a clean one.
Inspection and acceptance: what "clean" has to mean before the job starts
An assessment that ends in the word "clean" has failed, because two people will read it two ways. Write three acceptance types instead. A visible standard, recorded with close photographs taken from the same angle before and after, positioned so they show texture and seam detail rather than gloss. A tactile or physical standard, such as no loose material released by running a hand or a wipe along a named seam. And a functional standard for the fittings: a discharge seat that closes and seals as it should, a hatch that clamps with no material sitting in the sealing line. For each of these, name who inspects, and keep the inspector separate from the person who did the work.
Because the tank carries feed, your acceptance standard is also a document about the load, and it usually has an owner outside the wash crew. Ask who sets it, whether the customer, the receiving plant or a written feed-safety requirement you hold defines it, and record that source in the assessment. Where a laboratory check is part of your contract, the assessment should say what a swab is taken from and while the surface is still wet or already dry, because the answer changes what the crew does. If nobody has such a requirement, write down that the standard is your own and date it.
Access, confined space and the parts of the site the machine cannot control
Most of the schedule is owned by the site rather than by the equipment, so the assessment should carry a section for it. Entry into a tank is a permission, not a task: written permit, atmosphere checked and recorded, a person stationed at the opening, and a rule for how the job stops. Lighting inside the tank decides what anyone can see and therefore what anyone can sign off. Height and the position of the manhole decide where a person can stand and where a lance cannot reach. Drainage decides everything else: where the mixture leaves the tank, which gully or drain it enters, whether the yard is allowed to discharge that mixture there at all, and who grants it.
Add the practical limits while you are thinking about them. Where the wash takes place and how long the bay or yard can be held. How the tanker is held so it cannot roll or move while someone is inside. Which services are at that position, and how far the crew has to walk back for water. Whether the tank can be dried inside in the time available, in the weather you can expect in the season you are planning for, and what happens when it cannot. A plan that assumes warm drying in a cold month will be quietly abandoned in the second month, so the assessment should record the alternative.
Water, containment and where the wash residue is allowed to go
A tanker wash releases solids and a lot of liquid at once. The assessment should capture the solids before the liquid moves: dry scraping or blowing out of the cone and hopper, a screen at the discharge point, and a decision about who empties whatever the screen catches. Then decide the water in advance rather than during the job, because the two levers available are the volume of liquid and the time it is allowed to sit on a surface, and both are inside your control. Low-volume methods reduce what you have to contain; they do not by themselves remove a fatty film, which is why the deposit typing above has to come first.
Record where run-off is permitted, who said so, and when. Record whether the same route is used again the same day and whether the sump or settled box can be emptied at all. A cost line belongs here too: capture, screening and disposal of a feed-rich wash residue are usually the items that make an otherwise simple wash expensive, and an assessment that omits them produces a surprise invoice rather than a clean tank.
What the assessment must ask about the equipment, in writing, for one machine
Treat the catalogue as a starting point and put every deciding item to the supplier as a row to be answered for the exact unit being quoted. Do not accept an answer that applies to a range, and do not carry a row from one model to another, because the published pages in a range genuinely differ. For a machine proposed for this duty, the list should include: what the supplier states as delivered temperature and as delivered pressure, and where each is measured; whether those figures describe the generator or the point where the lance meets the surface; the heating rating and the supply it needs, checked against what exists at your wash position; how the machine takes water, and what fitting it wants against the tap you actually have; the volume of any tank on the machine, kept as a separate answer from how long the machine can run; how long it can work before it stops for water, and how long restarting takes; what protection features are fitted, asked for by name rather than as a count; whether extraction or vacuum is available on the unit being quoted, since some listed models carry a vacuum row and others do not; the hose and lance lengths, and whether the reach clears the discharge cone; and what is covered, by whom, and how quickly a part arrives.
Three cautions belong beside that list. A power rating is not an electricity bill. A tank volume is not working time. A temperature on a data sheet describes the generator and not necessarily what reaches the weld seam. If the figures matter to your decision, ask for the test condition behind each one and keep the reply. If your tanker duty needs a fixed position, a different reach, or a containment arrangement built around the bay, that is an engineering question rather than a catalogue question, and it is worth raising as such instead of hoping a listed model will stretch to it.
The trial: prove it on one tank, with the conditions written first
Do not decide a fleet programme on a demonstration. Mark off one or two areas in the cone and on one wall with tape, photograph them as they stand from an angle that shows texture and seam detail, and write the stop conditions before any liquid is applied: seal or coating lifting, material driven into a seam that cannot be inspected afterwards, water entering a bearing or a seat, or a residue that cannot be lifted from the panel. Run the trial with the tank otherwise empty, keep the run-off where you said it would go, and photograph the same panels again after a full discharge cycle rather than only while the surface is still wet.
Time the job from the second run rather than the first, and include the parts that are always left out: entry and exit, the walk to the water point, waiting for the machine to come back after a refill, and the drying step. Inspect the panel the next shift, when anything the wash loosened has had a chance to show itself. A figure from a single measured run, on one tank, in one season, is the only basis you can defend; anything else is a hope dressed as a number.
Structure of the finished assessment document
A usable assessment fits on a small number of pages and lives at the wash point. It contains: the scope, naming which tanks and which commodities it covers; the interior surface list with the four columns; the exclusion list with a replacement and its trade for each row; the acceptance standard for each named row and the inspector's name; the entry permit and stand-by rule; the water, drainage and containment route with the permission recorded; the equipment rows answered in writing for the quoted unit, with the answers dated and attributed; the trial result with photographs attached; the residual risks and who accepted them; the owner of the document and the next review date. Add one page per tank type trained at the tank, with a defect route written against each row, so the document survives the people who wrote it.
Finally, be clear about what this article cannot give you. It contains no figure, no interval, no saving and no consumption number, because none of those can be honest before your tank has been walked, your own standard written, and one bounded trial measured on your yard. An assessment that carries those items from somebody else's brochure is the one defect this document exists to prevent.
