In Brief
Tank crack repair on a silo trailer requires TDT-certified welding and a special TDT review before returning to service. Repair time: 2–4 days plus 5–10 days for TDT inspector. Free assessment on request.
A tank crack on a silo trailer immediately excludes the vehicle from pressurised operation. There is no option to apply a temporary sealant and “drive to the workshop” — the 2–3.5 bar working pressure in the tank creates a risk of sudden rupture when a weld is compromised.
PHS Magnum has TDT-certified welders for pressure vessels and manages the complete repair cycle: from assessment through welding to the special TDT review with the inspector on-site.
Where silo trailer tanks crack
Cracks do not appear randomly. With 30 years of repair experience we know that 80% of cases involve a handful of recurring locations:
Hatch flanges and welds — intensive hatch use (opening, closing, transport vibration) concentrates stress at the flange-to-wall weld. Cracking typically initiates in the heat-affected zone of the old weld.
Brackets and mounting points — components welded to the tank (hose brackets, ladder supports, pipework mounts) transmit vibrations directly into the tank wall. After years of vibration — fatigue failure at the bracket weld.
Discharge nozzle and lower fittings — pressure vessel, cargo weight, unloading forces. Welds at discharge nozzles operate under demanding conditions.
Side walls at lower edges — on older trailers after 12–15 years, especially those carrying cement or lime. The alkaline medium penetrates micro-cracks and expands them through stress corrosion cracking.
Pressure vessel repair procedure
Step 1 — Assessment and quotation (1–2 hours)
Tank inspection in the workshop or based on photographs. Identification of all damage (some cracks are invisible to the naked eye — we use dye penetrant testing). Written quotation.
Step 2 — Preparation for welding
Tank emptied and cleaned. Weld preparation: grinding, edge bevelling. If a plate section requires replacement — cutting and fitting.
Step 3 — Welding by certified welder
TIG welding of aluminium or MIG/MAG welding of steel by a TDT-certified pressure vessel welder. Full documentation: welder qualification, welding parameters, filler material, acceptance certificates.
Step 4 — Weld inspection and pressure test
Visual weld inspection (regardless of repair size). For larger repairs: dye penetrant or ultrasonic testing. Pressure test before TDT review.
Step 5 — Special TDT review with TDT inspector
After every pressure vessel repair a TDT inspector carries out the special review. PHS Magnum arranges the inspector’s visit — appointment 5–10 working days after repair completion.
Post-repair documentation
Complete document set after pressure vessel weld repair:
- Repair record with welding parameters
- TDT welder certificates
- Material certificates (plate, filler material)
- Pressure test results
- Special TDT review record / new TDT certificate
This documentation is required to maintain the validity of the TDT certificate and forms part of the vessel register.
Repair vs. new tank — economics
A new silo trailer tank requires multi-week procurement and installation. Even extensive weld repairs are completed in a fraction of the time and cost. For trailers under 15 years old, repair is almost always economically justified. Contact us for a specific quotation.
Exception: extensive pitting corrosion of tank walls (>30% of surface area below minimum permitted wall thickness) — weld repair is not possible in this case.
Contact
Tel: +48 602 716 551
Email: biuro@magnumchorula.pl
ul. Kościelna 9, 47-316 Chorula · 4 km from Prądy junction, A4 Opole West
Related: Silo trailer service · TDT inspections · Paint renovation · Spare parts