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What Is Periodic Inspection? A Legal Compliance Guide for Businesses
Periodic inspection is the examination of work equipment at defined intervals with measurement, trials and a signed report. This guide walks through the legal basis, the intervals per equipment family, what the control does and why the report is critical for your operation.
Periodic inspection is the mandatory process of examining the machines, equipment and installations at your workplace at defined intervals: competent examination engineers perform visual inspection, measurement, function trials and, where required, non-destructive testing; results are compared with limit values and sealed in a signed report. The purpose is to catch the fault before the accident, protect life safety and meet the legal duty with a document. You can find the full scope under our periodic inspection services.
Why Is It a Legal Requirement?
Law No. 6331 on Occupational Health and Safety obliges the employer to have work equipment inspected, maintained, measured and tested — and to document the results. Method and intervals are defined by the Regulation on Occupational Health and Safety in the Use of Work Equipment and the relevant standards. A missing control produces administrative fines, heavier legal liability in an accident and insurance-compensation risk.
Unless legislation or the standard sets another period, the interval cannot exceed one year. On pressure vessels the proof runs at 1,5 times operating pressure; for racks TS EN 15635 asks a yearly expert audit plus monthly user observation. Where the manual is shorter, the narrowest period prevails.
Which Equipment, How Often?
| Equipment / Installation | Interval | Basis |
|---|---|---|
| Pressure vessels, boilers | Yearly (proof at 1,5x pressure) | Work Equipment Regulation, Boiler Code |
| Cranes, forklifts, hoists, pallet trucks | Yearly | Regulation Annex III, TS EN 13001 |
| Electrical installation, earthing, RCD | Yearly | Internal Electrical / Earthing Regulations |
| Fire extinguishing-detection systems | Yearly (+ monthly visual) | Fire Buildings Regulation, TS EN 54 |
| Storage racks | Yearly expert + monthly visual | TS EN 15635 / 15512 |
| Machines and tools | Yearly | Machinery safety, TS EN ISO 12100 |
| Work machinery | Yearly | Work Equipment Regulation, TS EN 474 |
What Happens During the Control?
- Visual examination: corrosion, crack, deformation, missing-loose parts, guard integrity.
- Measurement and proof: wall thickness (UT), insulation and earth continuity, contact resistance, brake and safety-valve set pressures, live thermal scanning.
- Function test: emergency stop, light curtain, limit switches, automation-interlock chain.
- Reporting: a signed finding-levelled report, removal suggestion and the reference baseline for the next control.
Why the Report Is Critical
The periodic inspection report is the official engineering document asked for in Ministry of Labour audits, SGK accident investigations, courts and insurance expertise. Per the regulation it must be kept through the equipment service life and at least 5 years after decommissioning. Every report is the comparison baseline of the next control: the operator that reads trends manages the fault with a maintenance plan instead of buying it. For family-specific guides see our pressure vessel and lifting machine inspection pages.
Author: KYF Test Engineering Team • Last updated: September 2026