— A Practical Guide for Engineers, EPCs, and Project Teams
The Factory Acceptance Test (FAT) is the formal checkpoint where the instrument supplier, EPC contractor, and end user verify that equipment meets the project's technical, quality, and documentation requirements before it leaves the manufacturing facility. A well-executed FAT prevents defective or non-compliant instruments from reaching the construction site, where correction becomes far more expensive and disruptive.
For EPC projects, FAT is not a formality. It is a risk management gate. A missing Ex certificate, an incorrect calibration range, or an unverified material certificate discovered at FAT is a manageable issue. The same issue discovered during commissioning can delay start-up, trigger contractual penalties, and damage the reputation of everyone involved.
This guide explains the purpose, scope, inspection requirements, testing procedures, and documentation obligations for industrial instrumentation FAT.
1. What Is FAT?
A Factory Acceptance Test is a documented inspection and test process conducted at the manufacturer's facility. It confirms that:
The equipment matches the approved technical specification
Materials of construction are correct and traceable
Calibration and functional performance meet project requirements
Certifications (Ex, SIL, material, calibration) are valid and complete
Documentation packages are complete and accurate
Packaging, marking, and shipping preparation meet project requirements
FAT vs SAT:
| Aspect | FAT (Factory Acceptance Test) | SAT (Site Acceptance Test) |
|---|---|---|
| Location | Manufacturer's facility | Project site |
| Purpose | Verify equipment before shipment | Verify equipment after installation |
| Scope | Manufacturing quality, calibration, documentation | Installation integrity, loop checking, system integration |
| Timing | Before shipment | After installation, before commissioning |
FAT verifies the product. SAT verifies the installation. Both are required for a complete quality assurance program.
2. Why FAT Matters for EPC Projects
| Risk Without FAT | Consequence |
|---|---|
| Non-compliant materials | Corrosion, premature failure, safety incidents |
| Incorrect calibration | Measurement errors, control instability, product quality issues |
| Missing Ex certification | Regulatory non-compliance, inability to energise in hazardous areas |
| Incomplete documentation | Delayed turnover, punch list items, client rejection |
| Incorrect process connection | Rework at site, schedule delays |
| Undetected manufacturing defects | Commissioning delays, unplanned downtime |
| Packaging damage | Equipment damage during transport, replacement delays |
The economic case: The cost of conducting a FAT is a fraction of the cost of correcting a problem after shipment. A single missed Ex certificate can delay a project by weeks and cost hundreds of thousands of dollars in standby labour and schedule impact.
3. When Does FAT Occur?
FAT occurs after manufacturing is complete but before shipment. The typical sequence is:
| Phase | Activity |
|---|---|
| 1. Purchase order | Technical specification, inspection and test plan (ITP), FAT requirements agreed |
| 2. Manufacturing | Instruments manufactured, calibrated, and prepared for test |
| 3. FAT notification | Supplier notifies EPC/client of readiness, typically 2–4 weeks in advance |
| 4. FAT execution | Inspection and testing conducted at supplier's facility |
| 5. Punch list resolution | Any non-conformances corrected and re-verified |
| 6. FAT sign-off | Formal approval to ship |
| 7. Shipment | Equipment packed and shipped to site |
Key contractual point: The purchase order should specify:
Whether FAT is witnessed by the EPC, client, or both
The scope of FAT (100% or sampling)
The notice period required
The acceptance criteria
The documentation deliverables
4. FAT Scope by Instrument Type
FAT requirements vary by instrument type. The following table summarises typical FAT activities.
| Instrument Type | Visual Inspection | Dimensional Check | Functional Test | Calibration Verification | Documentation Review |
|---|---|---|---|---|---|
| Pressure transmitters | Yes | Yes | Yes | Yes | Yes |
| Temperature transmitters | Yes | Yes | Yes | Yes | Yes |
| Level instruments (radar, DP) | Yes | Yes | Yes | Yes | Yes |
| Flow meters (mag, vortex, Coriolis) | Yes | Yes | Yes | Yes | Yes |
| Pressure gauges | Yes | Yes | Sampling | Sampling | Yes |
| Thermowells | Yes | Yes | Pressure test | — | Yes |
| Manifolds and valves | Yes | Yes | Pressure/leak test | — | Yes |
| Junction boxes | Yes | Yes | Continuity | — | Yes |
| Instrumentation cables | Yes | Yes | Electrical tests | — | Yes |
| Control panels | Yes | Yes | Functional test | — | Yes |
Note: For bulk items (cables, gauges, manifolds), FAT may be based on sampling rather than 100% inspection, as defined in the ITP.
5. Pre-FAT Preparation
Proper preparation ensures the FAT is efficient and meaningful.
5.1 Documentation Review Before FAT
Before travelling to the supplier's facility, the EPC should review:
| Document | What to Verify |
|---|---|
| Approved datasheets | Confirm the latest revision matches the purchase order |
| Approved drawings | Confirm dimensional and connection details |
| Inspection and Test Plan (ITP) | Confirm the scope of FAT and witness points |
| Calibration procedures | Confirm calibration method and traceability |
| Material certificates | Confirm EN 10204 3.1 or 3.2 certificates are available |
| Ex certificates | Confirm validity, zone, gas group, and temperature class |
| SIL certificates | Confirm SIL rating and any limitations |
| Quality plan | Confirm inspection and test records are complete |
5.2 FAT Agenda
The supplier should provide a FAT agenda in advance, including:
Date, time, and location
List of instruments to be tested
Test equipment to be used (with calibration certificates)
Personnel involved (supplier, EPC, client)
Sequence of tests
Expected duration
5.3 Test Equipment Verification
All test equipment used during FAT must have:
Current calibration certificates traceable to national standards
Calibration due dates after the FAT date
Adequate accuracy (typically 4:1 ratio to the instrument under test)
6. FAT Inspection Checklist
Inspection verifies that the physical equipment matches the approved design.
6.1 General Inspection
| Check | What to Verify |
|---|---|
| Tag number | Matches the instrument index and datasheet |
| Model number | Matches the approved datasheet |
| Serial number | Recorded for traceability |
| Manufacturer | Matches the approved vendor |
| Nameplate | Correct tag, model, range, Ex marking |
| Workmanship | No visible damage, corrosion, or defects |
| Paint/coating | Correct colour and finish |
| Labelling | Tag plate, warning labels, terminal markings |
6.2 Dimensional Inspection
| Check | What to Verify |
|---|---|
| Overall dimensions | Match the approved outline drawing |
| Process connection | Type, size, and rating match the specification |
| Cable entry | Size, type, and orientation match the specification |
| Mounting | Bracket, holes, and orientation match the installation drawing |
| Weight | Within specified tolerance |
6.3 Material Inspection
| Check | What to Verify |
|---|---|
| Wetted materials | Match the approved datasheet (316L SS, Hastelloy, etc.) |
| Housing material | Match the specification |
| Material certificates | EN 10204 3.1 or 3.2 certificates available and traceable |
| Heat numbers | Traceable to material certificates |
6.4 Ex and Safety Inspection
| Check | What to Verify |
|---|---|
| Ex marking | Correct zone, gas group, temperature class |
| Ex certificate | Valid, current, and covers the specific model |
| Ex components | Cable glands, blanking plugs, seals are Ex-certified |
| SIL marking | SIL rating matches the safety function requirement |
| SIL certificate | Valid and covers the specific model |
7. FAT Testing Checklist
Testing verifies that the instrument functions correctly and meets performance specifications.
7.1 Calibration Verification
| Test | Method | Acceptance Criteria |
|---|---|---|
| Zero check | Apply 0% input | Reading within specified tolerance |
| Span check | Apply 100% input | Reading within specified tolerance |
| Mid-point check | Apply 25%, 50%, 75% input | Reading within specified tolerance |
| Repeatability | Apply same input multiple times | Within specified repeatability |
| Hysteresis | Increase and decrease input | Within specified hysteresis |
Typical tolerance: ±0.1% to ±0.5% of span, depending on the instrument accuracy class.
7.2 Functional Tests
| Test | Method | Acceptance Criteria |
|---|---|---|
| Power-up | Apply correct power supply | Instrument initialises correctly |
| Output signal | Measure 4–20 mA output | Matches the applied input |
| HART communication | Use HART communicator | Device responds; parameters readable |
| Alarm/trip output | Simulate alarm condition | Output activates correctly |
| Local display | Verify LCD reading | Matches the output signal |
| Zero/span adjustment | Adjust zero and span | Output changes correctly |
7.3 Pressure and Leak Tests
| Test | Method | Acceptance Criteria |
|---|---|---|
| Hydrostatic test | Apply 1.5× design pressure | No leaks; no deformation |
| Leak test | Apply design pressure; soap bubble test | No bubbles |
| Proof test | Apply specified proof pressure | No permanent deformation |
| Vacuum test | Apply vacuum (if applicable) | No leakage; stable reading |
7.4 Electrical Tests
| Test | Method | Acceptance Criteria |
|---|---|---|
| Insulation resistance | Apply 500V DC | >100 MΩ |
| Dielectric strength | Apply specified voltage | No breakdown |
| Continuity | Check conductor continuity | <1 Ω |
| Polarity | Verify + and - | Correct polarity |
7.5 Instrument-Specific Tests
| Instrument | Test | Acceptance Criteria |
|---|---|---|
| Pressure transmitter | Apply pressure; verify output | Within accuracy specification |
| Temperature transmitter | Simulate RTD/TC; verify output | Within accuracy specification |
| Radar level transmitter | Simulate level; verify output | Within accuracy specification |
| Magnetic flowmeter | Simulate flow signal; verify output | Within accuracy specification |
| Vortex flowmeter | Simulate flow signal; verify output | Within accuracy specification |
| Coriolis flowmeter | Verify density and mass flow | Within accuracy specification |
8. FAT Documentation Requirements
Documentation is half the value of FAT. Incomplete documentation can delay shipment, customs clearance, and project turnover.
8.1 Documentation to Be Reviewed at FAT
| Document | Content | Acceptance Criteria |
|---|---|---|
| Material certificates | EN 10204 3.1 or 3.2 | Traceable to heat numbers; matches specification |
| Calibration certificates | Calibration results | Traceable to national standards; within tolerance |
| Test reports | FAT test results | Complete; signed; matches ITP |
| Ex certificates | ATEX, IECEx, CCC Ex | Valid; covers the specific model |
| SIL certificates | Functional safety | Valid; covers the specific model |
| Outline drawings | Dimensional drawings | Match approved drawings |
| Wiring diagrams | Terminal connections | Match approved drawings |
| Installation manuals | Mounting and connection | Complete; in required language |
| Operation manuals | Configuration and operation | Complete; in required language |
| Maintenance manuals | Calibration and repair | Complete; in required language |
| Packing list | Items shipped | Matches purchase order |
| Certificate of origin | Country of origin | As required for customs |
8.2 Documentation Format
| Requirement | Specification |
|---|---|
| Language | English (or project-specified language) |
| Format | PDF (electronic) and hard copy (if required) |
| Organisation | Indexed and tabbed by document type |
| Revision | Latest approved revision |
| Signatures | Authorised signatories |
8.3 Documentation Delivery
| Timing | Requirement |
|---|---|
| Before FAT | Draft documentation available for review |
| At FAT | Final documentation available for verification |
| After FAT | Final approved documentation submitted |
| With shipment | Hard copies and/or electronic media |
| Before turnover | Complete as-built documentation package |
9. Roles and Responsibilities
| Role | Responsibility |
|---|---|
| Supplier | Prepare equipment; provide test equipment; provide documentation; conduct tests |
| EPC contractor | Review documentation; witness FAT; verify compliance; sign off |
| End user / client | Witness FAT (if required); approve deviations; accept equipment |
| Third-party inspector | Witness FAT (if required); verify compliance; issue report |
| Quality assurance | Verify ITP compliance; review documentation; approve release |
Witness vs. review: "Witness" means attending the FAT in person. "Review" means reviewing documentation without attending. The purchase order should specify which applies.
10. Acceptance Criteria and Punch List
10.1 Acceptance Criteria
FAT acceptance is based on:
All inspection items pass
All tests meet specified tolerances
All documentation is complete and correct
All certifications are valid and applicable
No outstanding punch list items that affect shipment
10.2 Punch List
A punch list records any non-conformances found during FAT.
| Punch Item | Description | Responsible Party | Status |
|---|---|---|---|
| 001 | Calibration certificate missing for PT-101 | Supplier | Open |
| 002 | Ex certificate does not cover the specific model | Supplier | Open |
| 003 | Terminal marking incorrect on FT-103 | Supplier | Closed |
Punch list categories:
| Category | Definition | Action |
|---|---|---|
| Category A | Critical; prevents shipment | Must be resolved before shipment |
| Category B | Major; affects function or compliance | Must be resolved before shipment or by agreed date |
| Category C | Minor; cosmetic or documentation | May be resolved at site or by agreed date |
10.3 FAT Sign-Off
FAT is formally closed when:
All Category A and B punch items are resolved
All documentation is complete
The FAT report is signed by all parties
Shipment release is authorised
11. Common Mistakes to Avoid
| Mistake | Consequence | Prevention |
|---|---|---|
| No FAT specified in purchase order | No formal verification before shipment | Specify FAT requirements in the PO |
| Insufficient notice for FAT | EPC/client cannot attend | Require 2–4 weeks' notice |
| Test equipment not calibrated | Invalid test results | Verify calibration certificates |
| Documentation incomplete at FAT | Delayed shipment; punch list items | Require documentation review before FAT |
| Ex certificate not covering the model | Regulatory non-compliance | Verify certificate covers the specific model |
| Calibration tolerance not specified | Disputes over acceptance | Specify tolerance in the PO |
| No punch list tracking | Items forgotten; shipment delayed | Track all punch items to closure |
| FAT report not signed | No formal acceptance | Require signatures from all parties |
| As-built documentation not updated | Documentation does not match equipment | Update documentation after FAT |
| Packaging not inspected | Equipment damaged in transit | Include packaging inspection in FAT |
12. Applicable Standards
| Standard | Scope |
|---|---|
| ISO 9001 | Quality management systems |
| IEC 61508 / IEC 61511 | Functional safety—SIL requirements |
| IEC 60079 | Explosive atmospheres—equipment certification |
| EN 10204 | Metallic products—types of inspection documents |
| ISO/IEC 17025 | Competence of testing and calibration laboratories |
| API RP 551 | Process measurement instrumentation |
| ISA-5.1 | Instrumentation symbols and identification |
| ISA-20 | Specification forms for process measurement and control instruments |
| IEC 60529 | Ingress protection (IP code) |
13. Why Choose Anhui Tiankang for FAT-Ready Instrumentation?
Anhui Tiankang (Group) Co., Ltd. has nearly five decades of experience in industrial instrumentation. We support FAT with complete documentation, calibrated test equipment, and experienced engineering personnel.
FAT capabilities:
| Capability | Details |
|---|---|
| Calibration laboratory | CNAS-accredited; traceable to national standards |
| Test equipment | Calibrated pressure, temperature, and electrical test equipment |
| Documentation | Complete material certificates, calibration certificates, test reports |
| Ex certification | CCC Ex, ATEX, IECEx for hazardous area instruments |
| SIL certification | SIL2/SIL3 for safety instrumented functions |
| Witnessed FAT | EPC and client witnessing supported |
| Punch list resolution | Fast turnaround on non-conformances |
Product portfolio for FAT:
| Product | FAT Scope |
|---|---|
| Pressure transmitters | Calibration, functional test, Ex verification |
| Temperature transmitters | Calibration, functional test, Ex verification |
| Level instruments | Calibration, functional test, Ex verification |
| Flow meters | Calibration, functional test, Ex verification |
| Pressure gauges | Sampling inspection, calibration |
| Thermowells | Dimensional, material, pressure test |
| Manifolds and valves | Pressure test, leak test |
| Instrumentation cables | Electrical test, fire performance verification |
Core advantages:
Complete certifications: CCC Ex, ATEX, IECEx, SIL
CNAS-accredited laboratory: full performance testing
Long-term supplier to CNPC, Sinopec, CNOOC, and international EPC projects
One-stop supply: from instruments to cables to Ex accessories
14. Conclusion
The Factory Acceptance Test is a critical quality assurance gate for industrial instrumentation. It verifies that equipment meets the project's technical, quality, and documentation requirements before shipment—preventing costly rework, schedule delays, and safety risks at the construction site.
Key takeaways:
| FAT Phase | Key Activity |
|---|---|
| Preparation | Review documentation, agree ITP, prepare test equipment |
| Inspection | Visual, dimensional, material, Ex, and safety checks |
| Testing | Calibration, functional, pressure, leak, electrical tests |
| Documentation | Material certificates, calibration certificates, test reports, Ex certificates |
| Acceptance | Punch list resolution, formal sign-off, shipment release |
The most important rule: FAT is not a formality—it is the last opportunity to catch problems before they leave the factory. A thorough FAT saves time, money, and reputation.
Remember: The cost of a FAT is a fraction of the cost of correcting a problem at site. The documentation you review at FAT is the same documentation that will be used for commissioning, maintenance, and regulatory compliance for the life of the plant.
Contact Us
For FAT support, instrument documentation, or project quotations, please contact:
Yin Shuangjie
International Sales Manager
📧 Email: [email protected]
📱 WhatsApp / Zalo: +86 17856068126
🌐 Website: http://www.tiankang-global.com/
Anhui Tiankang – Your partner for reliable instrumentation and FAT support.
