In Brief
TDT inspection is required every 2 years for silo trailers and cement tankers operating in Poland and the EU. A TDT inspector tests tank pressure and checks fittings, hoses, gauges, hatches and welds. Most common failure points: leaking safety valves, corroded hatch seals, out-of-date manometers, visible weld cracks. PHS Magnum provides full TDT preparation — parts replacement, documentation, and TDT inspector coordination — typically completed in 2–5 working days.
Every owner of a silo trailer or cement tanker is legally required to submit their vehicle to a TDT inspection every two years. Without a valid TDT certificate, the vehicle cannot legally operate on public roads in Poland and the EU — consequences include fines, an out-of-service order, and insurance complications.
What Is TDT and Who Performs the Inspection?
TDT – Transportowy Dozór Techniczny (Technical Transport Supervision) is a Polish government agency under the Ministry of Infrastructure that oversees the technical condition of vehicles transporting pressurized bulk goods. A TDT inspector performs the internal inspection and pressure test of the tank.
Workshops authorized to prepare vehicles for TDT inspection must hold a TDT authorization. PHS Magnum has held this authorization for over 20 years.
Which Defects Most Often Lead to Failure?
From our extensive experience, vehicles most often fail inspection for the following reasons:
- Tank corrosion – especially around nozzles and manholes. Rust below the minimum permitted wall thickness disqualifies the tank.
- Leaking shut-off and safety valves – even a minor leak during the pressure test means failure.
- Defective pressure gauges and thermometers – measuring instruments must have current calibration certificates.
- Missing or illegible nameplates – every pressure vessel must be fully marked with CE/PED identification.
- Outdated technical documentation – missing “vessel log” or an unupdated repair history.
- Mechanical damage to fittings and nozzles – accident-related deformations that alter the sealing geometry.
Our 4-Step Preparation Process for TDT Inspection
At PHS Magnum, we don’t send clients in unprepared. We prepare the vehicle so that the inspection becomes a formality.
| Step | What We Do |
|---|---|
| 1. Consultation | Phone review of vehicle history, recent repairs, and obvious defects |
| 2. Service inspection | Comprehensive check of pneumatic system, fittings, tank and documentation |
| 3. Repair | Fixing all disqualifying defects – welding, valve replacement, calibration |
| 4. TDT inspection | Coordinating the appointment with the TDT inspector and assistance during the test |
How Long Does Preparation Take?
Typically 2–5 working days – depending on vehicle condition. Urgent cases are handled with priority. We strongly recommend not leaving the inspection to the last minute: the certificate expires on a specific date, and downtime for tractor and trailer costs money.
When Should You Start Thinking About the Next Inspection?
We advise clients to contact us at least 3 weeks before the certificate expires. This allows time for:
- a complete service inspection without time pressure,
- ordering any required spare parts (valves, seals, gauges),
- scheduling the earliest available TDT inspector appointment.
Location: Chorula near Opole, Poland – 4 km from the A4 motorway, 180 km from the German border. Invoicing in EUR available. ISO 9001:2015 certified.
Questions about TDT inspection for your trailer? Call us: +48 504 788 385 (Eng. Roland Sobota)
Related: TDT inspections · Silo trailer service · Spare parts
