Heat exchangers: document past duty without promising a new one
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A heat exchanger sold from a working process still needs a new suitability assessment for its next job. The useful sales evidence is its identity, construction and documented past duty. “Suitable for food”, “chemical duty” or “high pressure” can conceal more questions than they answer.
Start by identifying the type: for example, a gasketed plate unit or a shell-and-tube exchanger. That distinction changes which records a buyer will need. Keep the original model designation rather than reducing everything to a stainless-steel heat exchanger.
For a plate unit, plate material, gasket specification and plate arrangement are separate facts. One photograph of a shiny frame will not establish them.
Two sides of the same question
The seller can describe what the exchanger is and how it was used. The buyer's engineer must decide whether it can meet a proposed duty. Put those two tasks beside each other.
| Seller's documented past-duty information | Buyer's proposed-duty question |
|---|---|
| Fluids previously used on each side | Are the new fluids compatible with the documented construction? |
| Recorded temperatures and operating conditions | Can the proposed conditions be supported by the correct technical assessment? |
| Model, serial and original drawings | Do these documents match the fitted unit and current configuration? |
| Plate, tube and seal materials where documented | Are these materials appropriate for the new process? |
| Cleaning, maintenance and modification records | What further inspection or work is needed? |
| Connection sizes, orientation and overall dimensions | Will it fit the intended installation and service arrangement? |
Leave unavailable entries visibly blank or mark them unknown. An engineer can work with a declared gap. A guessed material specification is much harder to spot.
The Alfa Laval AQLine instruction manual illustrates why the distinction matters. Its nameplate guidance separates design limits from operating conditions and notes the role of gasket material in temperature limitations. Those instructions apply to the covered models; they do not establish limits for an unidentified exchanger.
Follow the identity through the records
Match the plate photograph to the drawing, service report and asset register. If an old invoice describes a different plate pack or seal set, establish whether it records work on this unit.
Explain changes in the sales particulars. “Original drawing supplied; later configuration not confirmed” gives a buyer a fair starting point. “As original specification” would imply more than the paperwork supports.
Dimensions also need a clear source. Distinguish measurements taken from the installed unit from dimensions copied from a manual covering several sizes. Accessible connection photographs can help an engineer understand the arrangement without anyone opening the equipment for a sales inspection.
Where pumps and tanks form part of the package, use the guides to industrial pump duty records and process tank histories. List each item separately, then explain the relationship. A package description should not imply that every component has been assessed for a new process.
Previous fluids deserve their own paragraph
Record what flowed through each side, rather than describing the exchanger simply as “water cooled”. That phrase may say nothing about the other fluid.
Gather dated cleaning records and any documents covering residues, leaks or repairs. State exactly what those records establish. A cleaning invoice does not automatically establish suitability for another product, and a past service visit does not prove the present internal condition.
The previous contents guide helps structure this disclosure. Where the history is incomplete, a specialist can advise what assessment is needed before inspection, movement or reuse. Do not arrange improvised opening or pressure testing to make a listing look more complete.
Decide what the buyer is being offered
An exchanger with an identifiable configuration and coherent records can be assessed more readily than an anonymous item. That may support a sale as a process asset. It does not guarantee a particular value or eliminate further work.
If the unit belongs to a cooling package, establish whether the process chiller is included and whether splitting the equipment leaves either description misleading.
Send UK Auction Group the identity photographs, available drawings and a short statement of past use. Flag unknown materials or internal condition at the start so the sale approach reflects the evidence.
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Sources
This guide gives general information. Equipment-specific, legal, tax and safety decisions may need a qualified adviser or competent specialist. The guides do not promise sale prices, fees or results.