Paperwork is not bureaucracy in this market. It is the difference between an offer and a question.
Material certificates
A material test report ties the heat number on the casting to a chemical composition and mechanical property result. On alloy, stainless and high-class valves it is the primary evidence that the valve is what the nameplate says.
Without it, a buyer has to assume the material based on markings, which is reasonable on a standard carbon steel valve and much less reasonable on a WC9 or duplex body.
Pressure and leak test records
A shell and seat test record shows the valve held pressure at the specified test conditions. It does not guarantee future performance, but it does show the valve was sound when it left the works or the repair shop.
On high-class and pipeline valves, test records are expected. On general utility valves they are a bonus.
Relief valve records
Relief valve paperwork is a category of its own: set pressure, capacity certification, test reports, repair records and the name of the shop that did the work. Because a relief valve is a safety device, buyers want the history even though they are buying it as surplus.
If the valve is out of test, that is a normal and acceptable state. What matters is that the record exists and is accurate.
Calibration and loop records
For control valves, calibration sheets, bench set records and loop drawings help. They show the actuator range, the trim characteristic and the failure mode, which are otherwise inferred from the nameplates.
These records rarely survive a stores cleanout, which is why they add disproportionate value when they do.
What to do when the paperwork is gone
Send what remains: the tag, the nameplate, the purchase record, the stores label, the packing list. Partial documentation is still useful, and it is always better than a claim that documentation exists when it does not.
If the file is genuinely empty, say so. The lot will be priced on condition and identification, which is a normal transaction rather than a problem.
Questions sellers ask
Do you buy valves with no paperwork?
Yes. Most surplus has none, and it is priced accordingly rather than rejected.
Are scanned certificates acceptable?
Yes. A clear scan or photograph of the certificate is fine for review.
Do you need the original certificates to resell?
Originals help, but a legible copy with the heat number visible is usually sufficient.