Summary
TDT inspection for a silo trailer – a legal requirement every two years. The TDT inspector verifies documentation (two years of service records), inspects the tank (VT), conducts a pressure test (1.25 × MOP for 30 minutes), and checks the pressure-relief valve and pressure gauge. The most common grounds for refusal: weld cracks, a defective relief valve, or missing service documentation. PHS Magnum prepares trailers for inspection: pre-inspection service, fault rectification, documentation compilation, and inspector appointment coordination. Contact: +48 602 716 551.
TDT Inspection for Silo Trailers – Everything You Need to Know
The pressure vessel on a silo trailer is a technical device subject to TDT (Technical Inspection Office) oversight under the Technical Inspection Act. Aleksy Pasternak covers the principles of technical supervision for silo trailers in detail. A full inspection is required every two years – without exception.
Why Is the TDT Inspection So Important?
A silo trailer operates under pressures of up to 2.2 bar during discharge. The tank is subject to cyclic pressure stresses, corrosion from the materials being transported, and mechanical damage.
A compromised tank can rupture – and at 2 bar, the forces involved are enormous. That is precisely why the law mandates regular inspections.
TDT Inspection – Step by Step
Before the inspection (PHS Magnum):
- Tank condition assessment – VT, plus PT testing where cracks are suspected
- Leak test (1.1 × MOP for 30 minutes)
- Pressure-relief valve check – does it open at the correct pressure?
- Documentation compilation: two years of service records, vessel passport, previous TDT certificate
During the inspection (TDT inspector):
- Documentation review
- External visual inspection of the tank
- Manhole inspection (internal inspection for larger tanks)
- Pressure test: inflation to 1.25 × MOP (e.g. 2.75 bar for a MOP of 2.2 bar) held for 30 minutes
- Pressure-relief valve test
- Issue of the certificate or a refusal decision
Most common grounds for refusal:
- Weld cracks (identified by PT or VT)
- Defective pressure-relief valve (fails to open, opens too early, or opens too late)
- Missing service records
- Corrosion losses in the tank wall (wall thickness below the calculated minimum)
Schedule: What to Do and When
A TDT certificate is valid for two years. Do not wait until the last day:
- 6 weeks before expiry: contact PHS Magnum, book a pre-inspection service
- 4 weeks before: rectify any faults, compile documentation
- 2 weeks before: schedule an appointment with the TDT inspector
- Day of inspection: clean, empty trailer with a complete set of documents
Contact: +48 602 716 551
Related: Spitzer Service · TDT Inspections for Silo Trailers – PHS Magnum · TDT Inspections · Spare Parts · Repair and Refurbishment · Annual Spitzer Trailer Service
