Buyers use two acceptance stages to keep valve quality from slipping through the gap between the factory and the field. A factory acceptance test (FAT) checks the manufactured valve, actuator, accessories, testing, and documents under controlled factory conditions before shipment. A site acceptance test (SAT) confirms that the installed assembly operates correctly with site utilities, controls, piping, and safety systems. Defining both boundaries prevents receiving nonconforming equipment or discovering interface problems late in commissioning.
FAT vs SAT: Where Each Acceptance Boundary Begins
A factory acceptance test is normally performed before shipment at the manufacturer’s facility or another agreed test location. A site acceptance test occurs after delivery and usually after installation. They are complementary rather than interchangeable.
FAT is important for EPC contractors, owner engineers, inspectors, and procurement teams buying engineered valves, actuated packages, control valves, safety valves, cryogenic valves, or assemblies with project-specific accessories. SAT becomes especially important when operation depends on site air, power, control signals, interlocks, piping alignment, or process integration.
| Acceptance item | Typical FAT focus | Typical SAT focus | Buyer action |
|---|---|---|---|
| Valve identity | Tag, size, class, materials, and purchase order match | Correct valve installed at the correct line location | Reconcile tag lists at both stages |
| Pressure boundary | Shell and closure tests under an agreed procedure | Site leak or integrity checks where required by the commissioning plan | Define test medium, pressure, duration, and acceptance criteria |
| Seat performance | Seat leakage test to the specified standard | Operational tightness checks if safe and practical | State allowable leakage rather than requesting only “zero leakage” |
| مواد | Material records, markings, and supplementary verification | Confirmation that delivered equipment matches released records | Identify components requiring traceability, PMI, or ferrite checks |
| محرک | Travel, torque or thrust settings, fail action, and accessories | Operation using actual site power or instrument air | Provide supply pressure, voltage, signal, and fail-position requirements |
| Controls | Solenoid, switches, positioner, and local control function | DCS, SIS, ESD, or field-network integration | Assign responsibility for logic and loop testing |
| End connections | Dimensions, flange details, weld ends, and protective covers | Alignment, gasket selection, bolting, and welding condition | Check drawings before release and installation |
| Visual condition | Coating, marking, cleanliness, preservation, and packing | Transit damage, contamination, and installation damage | Record condition with dated inspection evidence |
| Documents | Test records, material records, drawings, and certificates | Installation records, loop checks, punch list, and handover file | Use a document index with revision status |
| Maintainability | Access to adjustments and ordered spare parts | Physical access for operation, removal, and maintenance | Review clearance and orientation before commissioning |
The purchase order should identify which results permit shipment and which conditions must be proven at site. Without that division, a successful FAT may be incorrectly treated as proof that the complete installed system will work.
Freeze Valve Specifications Before Writing the Test Procedure
An acceptance procedure cannot compensate for an incomplete valve specification. Before approving the inspection and test plan, compare the datasheet, purchase order, approved drawing, and applicable project specifications.
- Valve definition: type, design, bore, flow direction, size, pressure class, and quantity by tag.
- Service conditions: medium, composition, solids, corrosive constituents, design and operating pressure, and minimum and maximum temperature.
- Construction: body, bonnet, closure member, stem, trim, seat, seal, packing, gasket, and bolting materials.
- Connections: flange standard and facing, butt-weld or socket-weld details, threaded standard, face-to-face dimension, and mating-pipe information.
- عملیات: manual gearbox or actuator type, available torque or thrust basis, fail action, travel time, power supply, signal, and hazardous-area requirements where applicable.
- Testing: governing standard, test medium, pressure, holding time, leakage class, witness points, and supplementary examinations.
- Deliverables: drawings, material records, test reports, calibration evidence, operating instructions, spare-parts list, and packing requirements.
Do not rely on a model number alone. The same valve family may have different seats, trims, pressure ratings, or actuator arrangements. Buyers should also confirm whether the quoted valve standard applies to design, dimensions, pressure testing, fire testing, emissions, or only one part of the requirement.
Build the Valve FAT Around Hold Points and Recorded Evidence
A practical valve FAT starts with document review and identification, then proceeds through visual, dimensional, pressure, functional, and final documentation checks. The sequence should prevent irreversible work or shipment before required hold points are released.
- Review the approved basis: confirm the latest drawing, datasheet, test procedure, inspection and test plan, and deviation register.
- Verify identity and traceability: compare nameplate and component markings with the tag list and material documentation.
- Inspect dimensions and construction: check end connections, face-to-face dimensions, operator orientation, accessory mounting, and accessible drain or vent points.
- Conduct specified tests: perform shell, seat, backseat, functional, torque, cryogenic, or other tests only as required by the order and applicable procedure.
- Verify the actuated package: test opening and closing, position indication, fail action, limits, switches, positioner response, and manual override as applicable.
- Close documentation: record results, instruments, calibration status, observations, nonconformities, corrective actions, and approval signatures.
Pressure test expectations may reference standards such as API 598, ISO 5208, API 6D, or project-specific requirements, depending on valve type and service. Buyers should state the governing edition and resolve conflicts before testing. Test safety, especially for pneumatic testing, requires an approved procedure and appropriate controls.
For alloy valves, material verification may be a separate witness point. Review the practical limits of PMI testing for valve alloy verification before deciding whether XRF or OES is suitable. Duplex material specifications may also require a defined method and acceptance range for ferrite testing in duplex valves.
If you are preparing a FAT specification, share the service medium, pressure, temperature, valve size, materials, standards, actuator details, and leakage requirements with JH Valve / Janhen Valve for a technical requirement review. This helps identify ambiguous acceptance points before the test procedure is finalized.
What the SAT Must Prove After Valve Installation
SAT should concentrate on conditions that cannot be fully reproduced during FAT. These include installation orientation, actual utility quality, field wiring, control-system communication, interlocks, piping loads, accessibility, and operation within the assembled system.
Before energizing or pressurizing the installation, the site team should check for transit damage, foreign material, removed transport restraints, correct flow direction, proper bolting, gasket compatibility, welding completion, and actuator support. For welded pipeline valves, installation planning may include pup pieces that protect valve seats and seals from welding heat.
A typical SAT sequence may include:
- Confirming valve tags against piping and instrumentation diagrams and line lists.
- Checking instrument-air pressure and quality, electrical supply, grounding, and signal type.
- Performing local open-close tests before remote operation.
- Verifying indicated position against actual valve travel.
- Testing alarms, permissives, fail positions, emergency shutdown logic, and partial-stroke functions where specified.
- Checking for external leakage under safe commissioning conditions.
- Recording stroke behavior, abnormal noise, binding, vibration, or unstable control response.
- Creating a punch list with responsibility, due date, retest requirement, and closure evidence.
SAT must not automatically repeat factory hydrostatic testing after installation. Field pressure tests can introduce contaminated media, overstress connected equipment, or damage sensitive seats and instruments. The commissioning team should use the approved project procedure and confirm isolation boundaries and safety controls.
Match Test Standards to the Valve Function
Standards should be assigned by purpose rather than copied into an RFQ as an undifferentiated list. One standard may govern design, another pressure testing, another face-to-face dimensions, and another actuator or leakage performance.
For each cited standard, buyers should record the edition, applicable clauses, acceptance values, and precedence if requirements conflict. A control valve may require functional checks and a specified leakage class that differ from isolation-valve testing. A pressure safety valve requires set-pressure and seat-tightness criteria appropriate to that device; buyers can review the distinction between a PSV pop test and seat leak test when defining witness points.
Standards compliance should be supported by relevant records, not inferred from a general statement on a quotation. Ask which tests are routine, which are supplementary, which require third-party witnessing, and which must be requested before manufacturing begins. Destination-market regulatory and conformity requirements should be independently confirmed for the project location.
Acceptance Gaps That Cause Delays and Disputes
The most expensive test problem is often not a failed valve but an undefined acceptance basis. Watch for these warning signs during bid clarification:
- “Standard testing included” without a named standard: request the standard, edition, test scope, medium, duration, and leakage limit.
- FAT and SAT used as interchangeable terms: assign the location, responsible party, prerequisites, and release authority for each activity.
- No witness notification period: agree how inspection invitations, waivers, and rescheduling will be managed without assuming an exact lead time.
- Unapproved substitutions: require deviations in writing and evaluate their effect on corrosion resistance, temperature limits, dimensions, and spare parts.
- Missing actuator utility data: confirm minimum and maximum air pressure, voltage, frequency, control signal, and required fail position.
- Incomplete traceability: define which pressure-containing and trim components must connect to material records and markings.
- Shipment before document closure: identify which documents are required for release and which may follow in the final dossier.
- SAT planned without installation prerequisites: require completed piping, utilities, loop checks, permits, and safe test boundaries.
Retain FAT evidence as the baseline for site troubleshooting. If a valve passed functional testing before shipment but binds at site, the team can investigate alignment, piping stress, contamination, supply pressure, wiring, or changed settings instead of repeating every factory inspection.
Prepare an RFQ That Produces Comparable FAT and SAT Plans
A technically complete inquiry allows suppliers and inspectors to price and schedule the same scope. Include the following information in the RFQ or attached datasheet:
Valve acceptance inquiry template
- Project, destination, tag numbers, quantities, and required document language
- Valve type, size, pressure class, design, bore, and end connection
- Media, design pressure, operating pressure, and temperature range
- Body, trim, seat, seal, packing, gasket, and bolting requirements
- Applicable design, dimensional, testing, and project standards with editions
- Actuator type, fail action, utility supply, accessories, signals, and operating time
- Required shell, seat, functional, material, low-temperature, emissions, or supplementary tests
- Inspection level, third-party involvement, review, witness, and hold points
- Acceptance criteria and required test records
- FAT location, SAT responsibility, site prerequisites, and retest responsibility
- Drawing, material record, calibration, operating manual, spare-parts, and final dossier requirements
- Preservation, packing, delivery coordination, and storage conditions
Compare quotations line by line. One supplier may include routine pressure testing but exclude witnessed testing, actuator integration, supplementary material examination, or site attendance. Clarify exclusions and deviations before commercial comparison rather than treating unlike scopes as equal.
Release the Valve Only When Evidence and Responsibilities Are Clear
Before authorizing shipment, verify that FAT punch items are closed or formally accepted, test records identify the tested valve, and approved deviations are reflected in drawings and documents. Before SAT, verify preservation removal, installation readiness, utilities, safety permits, and control-system availability.
Send JH Valve / Janhen Valve your valve datasheets, service conditions, applicable standards, actuator requirements, inspection plan, witness points, and document list for review before requesting a commercial quotation. A defined FAT and SAT boundary makes technical comparison clearer and reduces avoidable changes during inspection and commissioning.
سوالات متداول
Can SAT replace a valve FAT?
No. SAT confirms installation and system integration, while FAT verifies the manufactured valve and agreed factory tests before shipment. Omitting FAT can move correctable manufacturing or documentation problems to the project site.
Who should write the FAT and SAT procedures?
The responsible supplier or contractor often drafts the procedure, but the purchaser, EPC contractor, owner, inspector, and commissioning team should review the sections relevant to their responsibilities. The purchase order should identify approval and witnessing authority.
Does every valve require a witnessed FAT?
Not necessarily. The required inspection level should reflect valve criticality, service risk, customization, quantity, project specifications, and regulatory obligations. Buyers may use document review, witness points, hold points, or third-party inspection according to the approved plan.
What documents should be available after FAT?
The required dossier may include approved drawings, inspection records, pressure and functional test reports, material records, calibration evidence, nonconformity closure, operating instructions, and packing records. The exact list must be defined in the purchase order.
What happens if a valve passes FAT but fails SAT?
Compare the FAT baseline with site conditions before assigning cause. Check transit damage, contamination, piping alignment, actuator utilities, wiring, control logic, changed settings, and installation practices, then document corrective action and retest requirements.
Final Thoughts
Effective acceptance testing separates factory-verifiable valve quality from site-verifiable installation performance. Define specifications, standards, acceptance values, responsibilities, records, and release points before ordering. That preparation turns FAT and SAT into useful risk controls rather than last-minute inspection events.
