• ByRouging Solutions Editorial Team  ·  2 November 2026

Passivation Records for FAT and SAT: An OEM Handover Guide

The vessel is built, polished and ready to ship. Then the buyer's QA team arrives for the factory acceptance test and asks one question. Where are the passivation records? If the answer is a single line on a delivery note, the handover can stall. This guide is for OEMs and fabricators who build stainless steel equipment for pharma and food plants.

It covers what passivation records should hold, why buyers ask for them at FAT and SAT, and which tests prove the steel is passive. Getting these right means fewer repeat checks once the equipment reaches site.

What Are Passivation Records at Equipment Handover?

They are the papers that prove each wetted part of the equipment was passivated, how it was done and that it passed a test. They travel with the equipment from the workshop to the buyer's site. The buyer's QA team may review them at the factory acceptance test (FAT), the site acceptance test (SAT) and installation qualification (IQ).

Passivation is an acid treatment for stainless steel. It removes free iron, the loose iron specks left by cutting and welding. It helps the steel's thin chromium oxide layer form again. That layer is what stops rust. A buyer cannot see it, so the record is their main proof that the job was done.

These handover papers sit alongside the plant's own logs. Our guide on passivation documentation that fails audits covers the records a plant keeps after the equipment is in use. This guide covers the step before that: what the maker hands over.

Why Do Plants Ask OEMs for Passivation Records at FAT?

Because what is checked well at the factory may not need checking again at site. The EU's guide on qualification, EU GMP Annex 15, allows that. Where justified, it says "documentation review and some tests could be performed at the FAT" without repeating them at IQ or OQ. Weak records remove that option.

The same rule has a condition. The FAT result can only stand if "the functionality is not affected by the transport and installation." So buyers often check the records at FAT and the surfaces again at SAT. A record that is complete at the factory makes that second check quick.

Annex 15 also makes FAT a choice. Section 3.4 says equipment "may be evaluated, if applicable, at the vendor prior to delivery." Section 3.7 adds that "FAT may be supplemented by the execution of a SAT" once the equipment arrives. With or without a FAT, a buyer will usually want to see the passivation records before the equipment goes into use.

At IQ, Annex 15 lists two checks that touch your papers. One is "Verification of the materials of construction". The other is collecting the maker's operating and upkeep papers. Annex 15 does not name passivation records. Even so, many buyers file them in the same IQ pack.

US plants have their own reason. 21 CFR 211.67 says "Records shall be kept of maintenance, cleaning, sanitizing, and inspection". A buyer who sells to the US will want your records to fit into that system.

What Should a Passivation Record Contain?

Enough detail for a stranger to repeat the job and check the result. That comes down to seven fields. They cover the part, the method, the chemical's strength and temperature, the time and the rinse. The last two are the test result and who did the work. A record missing any of these will draw questions at FAT.

Other industries ask for similar fields. The Open Compute Project wrote a 2026 guide for data center cooling loops. It asks teams to "Record the date, passivation method used, chemical concentrations, exposure time and test results." Those cover parts of five of the seven fields above.

Which Tests Prove the Steel Is Passive?

ASTM A967 is the usual reference, and it offers a choice. Its scope says it "includes several alternative tests, with acceptance criteria". The buyer's spec or purchase order should name the one that applies. Agree it before work starts, so the test you run is the one the buyer will accept at FAT.

The ASTM A967 summary lists the tests. They are the "water immersion test, high humidity test, salt spray test, copper sulfate test, and potassium ferricyanide-nitric acid test." It also calls for a free iron test to check for loose iron on the surface. The current edition is A967/A967M-25.

Each test suits a different job, part size and setting. Our guide on passivation testing methods explains how each one works and when to use it.

A967 also sets what the surface should look like. Passivated parts "shall exhibit a chemically clean surface". On visual inspection, they should "show no etching, pitting, or frosting". Write the visual check into the record, too.

The rinse belongs in the record as well. A967 says that straight after the acid, parts "shall be thoroughly rinsed". It allows still, countercurrent or spray rinses, alone or together. Write down which one you used and the water quality, so the buyer can see no acid was left behind.

How Do FAT and SAT Records Fit Together?

They form one chain from the workshop to the plant. The URS sets what the buyer needs. The OEM passivates the equipment and records it. FAT reviews the records and the steel at the workshop. SAT can recheck the steel after transport. At IQ, the materials are checked and the papers filed.

Transport is the weak link. Scratches, road dust or water left inside during shipping can undo good work. Cap every opening and keep the equipment dry on the way. If any welding is done at site, the new welds need passivation and a fresh record of their own. Note any damage found at SAT in the same file, with photos, so each fix can be traced.

Our guide to passivation onsite or offsite helps you decide where each part of the job should happen.

What Gets Passivation Records Questioned at Handover?

Gaps, vague words and records that do not match the spec. The usual problems are easy to spot once you know them. A line that says "passivated as per ASTM" with no method, no test and no date is the classic case. So is a test result with no place, part or person named next to it.

Here are the gaps to check for before FAT:

1. No method named. "As per ASTM A967" is not enough, because the standard holds several methods.
2. No test result. A record that says "passivated" but shows no test leaves the buyer to take it on trust.
3. The wrong test. A test the buyer's spec does not list may have to be run again.
4. No link to the part. Without a tag number, nobody can say which vessel the record covers.
5. Site welds missing. New welds made at site often have no record at all.
6. Unsigned pages. A record with no name or date is hard to defend in an audit.

How Rouging Solutions Helps OEMs and Fabricators

We passivate equipment at your workshop or at our premises, and every job comes with all the relevant documents. Before work starts, we can agree with you which fields your buyer needs. Our team checks the surface with imported tools that are fully calibrated. We can also polish or electropolish the steel before we passivate it.

Our three directors bring 60+ years of combined industry experience. Fabricators with a steady flow of passivation work can bring it in-house. Our service for the establishment of a passivation system helps OEMs and pipe spool makers set up their own passivation system at their workshop.

Here is a made-up example of a complete record at work. Say a fabricator in Vadodara builds a mixing vessel for a plant near Hyderabad, with FAT set for November. The buyer's URS names a citric acid method and a high humidity test. The record lists both, with the tag number, times and signed results. FAT closes the passivation item in one review.

Where to Start

Remember one thing: the buyer cannot see passivation, so your record has to show it for you. Before your next FAT, pull out the last passivation record you sent to a buyer. Read it as if you were their QA team seeing it for the first time.

Check it against the seven fields in this guide. Mark any field that is missing or vague, and fix the form before the next job. If you need help with the passivation itself, or with setting up your own passivation system, call us. We reply within 24 hours.

Frequently Asked Questions