Electrical and assembly

Mechanical assembly and end of line testing: what goes wrong and where to inspect

Pumps, gearboxes, valves, machines and skids are assembled from many sourced parts and tested at the end of the line. This is where hidden supply chain problems finally show up.

ISO9001 ISO2859-1

01How the process works

Assembly brings together machined parts, bearings, seals, fasteners, electrical components and purchased equipment. Work instructions define sequence, torques, fits, lubrication and adjustments. End of line testing proves function: running, pressure, leak, noise, vibration and performance.

Contamination, wrong parts, missing torque and misalignment are typical assembly defects. Test results are only meaningful if instruments are calibrated and test procedures agreed in advance.

Kitting. Parts verified and cleaned.
Sub-assembly. Bearings, seals and modules assembled.
Final assembly. Sequence, torques, alignment.
Testing. Run, pressure, leak, performance tests.
Final inspection. Paint, nameplate, documents, packing.

02What typically goes wrong

Defect	Typical cause	How it is found
Contamination	Cleanliness of parts and area	Visual, cleanliness tests
Wrong or missing parts	Kitting errors	Visual against BOM
Missing torque	Tool or operator	Torque audit, marks
Misalignment and vibration	Assembly fits, alignment	Vibration measurement
Leaks	Seals, assembly damage	Leak test
Performance below spec	Component or assembly issue	Performance test

03Where an inspector should look

Before production

Work instructions and test procedures
Critical parts verified

During production

Torque and alignment checks
Cleanliness

After production

Run and performance tests witnessed
Nameplate, documents
Preservation and packing

04Standards and references

ISO9001 ISO2859-1

ISO 9906 (pump acceptance tests), ISO 10816 and ISO 20816 (vibration), API 610 for process pumps, Machinery Directive essential requirements.

Standards are named for orientation. The applicable edition and acceptance criteria are those in your contract and specification.

05How we support buyers of assembly and testing parts

Factory Acceptance Testing (FAT)FAT procedure review, readiness check, test witnessing, punch list management and acceptance recommendation. Mechanical Equipment InspectionInspection of rotating and static mechanical equipment: assembly, hardness, mechanical, load, pressure, leak and running tests. Pre-Shipment InspectionFinal random or complete inspection of finished goods before shipment: quantity, conformity, workmanship, packing and marking.