Chorula k. Opola 4 km from motorway A4 Mon-Fri 06:00-20:00
+48 602 716 551

TDT Inspection — Spitzer

TDT inspection for Spitzer SF and SK silo trailers: preparation, weld testing, pneumatic pressure test, documentation. ISO 9001 certified, Chorula near Opole.

DAF Magnum silo trailer fleet at PHS Magnum base

TDT Inspection for Spitzer Silo Trailers — Full Scope

Every Spitzer silo trailer (SF and SK series) is a pressure vessel subject to technical supervision under Polish law (TDT — Transportowy Dozór Techniczny). Periodic inspection every two years is mandatory — without a valid certificate, the trailer cannot legally participate in bulk material transport.

PHS Magnum in Chorula (4 km from the A4 motorway) is a specialist facility preparing Spitzer silo trailers for TDT inspections. We hold ISO 9001:2015 certification, employ welders certified to ISO 9606-2 (aluminium), and maintain all necessary diagnostic equipment. The TDT inspector from the Katowice regional office visits our workshop — we handle the scheduling.

TDT Inspection Scope (in accordance with the Minister of Infrastructure Regulation)

Visual Inspection of the Tank

  • External surface condition (corrosion, visible cracking, deformation)
  • Coating condition, particularly around weld zones
  • Mounting arrangement (fifth-wheel saddle, supports)
  • Nameplates (legible, complete, consistent with documentation)

Non-Destructive Testing (NDT) of Welds

The Spitzer TDT documentation specifies the required NDT methods:

  • MT (Magnetic Particle Testing) — for welds in ferromagnetic steels
  • PT (Penetrant Testing) — for non-magnetic materials (Spitzer aluminium tanks)
  • VT (Visual Testing) — always required

Spitzer silo trailers with aluminium tanks: PT + VT. Certain specialist models (steel underframe variants) may also require MT.

Pressure Test (Pneumatic)

  • Tank filled with compressed air
  • Test pressure: 1.25 × MOP (for Spitzer silo trailers, MOP is typically 1.0–2.2 bar, test 1.25–2.75 bar)
  • Hold time: 10–30 minutes
  • Visual inspection under pressure (no leaks permitted)
  • Pressure drop within test period must remain within acceptable limits

Pneumatic System Inspection

  • Safety valves (calibration, venting test at set pressure)
  • Pressure gauges (accuracy, legibility)
  • Auxiliary compressor and air dryer (if fitted)
  • Pressure sensors (if fitted)

Documentation

  • Previous TDT inspection certificate
  • Spitzer trailer technical data card (serial number, model, rated parameters)
  • Welding repair history (if applicable)
  • NDT test reports from previous repairs

PHS Magnum Preparation Package

Before calling the TDT inspector, we carry out a comprehensive preparation programme:

Step 1: Internal Cleaning

The tank must be empty, clean, and dry. Procedure:

  • Removal of residual bulk material
  • Water wash (with sanitisation for food-grade applications)
  • Drying with compressed air

Step 2: Internal Visual Inspection

Entry into the tank (following confined space procedures — restricted atmosphere, external standby). Inspection covers:

  • Internal lining condition
  • Internal welds
  • Aeration pad mounting points
  • Surface corrosion

Step 3: Preventive Repairs

Where the inspection reveals minor defects, we address them before the official inspection to avoid a negative assessment:

  • Minor surface welding (where micro-cracking is detected)
  • Manhole seal replacement (if worn)
  • Safety valve replacement (if calibration is out of tolerance)

Step 4: Internal Trial Pressure Test

We conduct a pressure test before the official inspection, under controlled conditions. If the trial test passes, the probability of a positive TDT outcome is very high.

Step 5: Documentation Compilation

We gather the vehicle’s complete history: previous inspection certificates, welding repairs, modifications. A complete documentation pack speeds up the inspection process and gives the TDT inspector confidence in the vehicle’s history.

Step 6: Inspector Scheduling

We arrange the visit with the Katowice regional TDT office. The inspector comes to PHS Magnum — your fleet avoids the logistical burden of transporting vehicles to inspection points.

Overall Process Timeline

  • Preparation: 1–2 working days (cleaning, inspection, any remedial repairs)
  • TDT inspection: 2–4 hours (examination, pressure test, documentation)
  • Certificate issuance: same day or next working day

Realistic end-to-end timeline (from trailer arrival at our workshop to departure with a valid TDT certificate): 2–3 working days in a standard case.

What Happens if the TDT Inspection Fails?

The TDT inspector may withhold the certificate where the following are identified:

  • Cracks in the pressure vessel
  • Surface corrosion exceeding permissible limits (typically wall thickness reduction >20%)
  • Documentation discrepancies
  • Defective safety valves
  • Other critical defects

PHS Magnum procedure:

  1. Written acknowledgement of inspector’s findings
  2. Repair plan with cost estimate (ask for a quote)
  3. Execution of repairs (typically 1–2 weeks depending on scope)
  4. Internal pressure test
  5. Re-scheduling of inspector visit
  6. Re-inspection

Thanks to our preparation package, the risk of a failed inspection is minimal — between 2024 and 2026, fewer than 5% of vehicles we prepared required a re-inspection.

Frequently Asked Questions

Periodic TDT inspection is required every 2 years (24 months from the previous inspection date as recorded in the TDT certificate). An extraordinary inspection is required after: accident-related repairs to the tank, any welding carried out on the pressure vessel, or significant structural modifications. Without a valid TDT certificate, the vehicle's registration lapses and it cannot legally operate on the road.

Full scope: visual inspection of the pressure vessel condition, non-destructive testing (NDT) of welds (PT penetrant testing, optionally UT ultrasonic testing, depending on documentation), pneumatic pressure test (compressed air to 1.25 × MOP), inspection of the pneumatic system (safety valves, pressure gauges, sensors), inspection of mounting brackets and supports, and verification of nameplates and documentation.

PHS Magnum's preparation package covers: 1) visual inspection of the tank with correction of any identified defects; 2) replacement of manhole gaskets and discharge valve seals if worn; 3) inspection and calibration of safety valves; 4) inspection and replacement of pressure gauges if inaccurate; 5) compilation of the vehicle's service history (previous inspection certificates, repair reports); 6) internal pre-inspection protocol.

Yes. The TDT inspector (Transportowy Dozór Techniczny — Poland's transport technical supervision authority) from the relevant regional office (in our case, TDT Katowice) visits the PHS Magnum workshop in Chorula. We schedule appointments 7–14 days in advance. The inspector carries out the inspection in our presence, and the inspection report is completed jointly.

The TDT inspector refuses to issue a certificate, providing written reasons (identified defects). The vehicle is prohibited from operating until the defects are rectified and a re-inspection is passed. PHS Magnum begins repairs immediately — crack welding (where detected), replacement of damaged components, and repeat testing. A re-inspection typically takes a further 1–3 weeks depending on scope. Our preparation package is specifically designed to minimise the risk of a failed inspection.

As of 2026, TDT certificates are issued in paper form, though TDT is developing an electronic system. Current requirements: the original certificate must travel with the vehicle (the driver must have access to it during roadside checks), a copy is held by the fleet operator, and a copy is held by PHS Magnum in the vehicle's service file.

TDT is a Polish legal requirement and applies to vehicles registered in Poland. For vehicles registered in Germany or Austria, the equivalent procedure is carried out by TÜV Nord, TÜV Süd, or the relevant regional authority. PHS Magnum can prepare a Spitzer silo trailer for a German inspection (the technical scope is identical to TDT), but the physical inspection must be conducted by a qualified TÜV inspector. We work with TÜV Hannover for our DACH clients.

Contact & Hours

ul. Kościelna 9, 47-316 Chorula

Mon-Fri 06:00-20:00

Sat 07:00–15:00

+48 602 716 551 Contact us
DEKRA ISO 9001:2015 Quality Management Certificate — PHS Magnum

ISO 9001:2015

4 km from motorway A4

180 km from German border

Call Email
Pogotowie Techniczne TIR & SILO +48 602 716 551