Mon–Fri 06:00–20:00  |  Sat 07:00–15:00 biuro@magnumchorula.pl
+48 602 716 551 |

Tank Welding

Accident welding of silo trailer tanks: TIG aluminium 5083/5754, 304L/316L stainless steel, NDT (MT/PT/RT), WPS, TDT inspection. ISO 9606 welders. Chorula near Opole, Poland.

TIG accident welding of a silo trailer tank — PHS Magnum

At a glance

Welding a silo trailer tank after an accident is the most rigorous repair on the vehicle — it requires a welder certified to ISO 9606, a WPS approved for the trailer, certified filler materials, non-destructive testing (NDT) and an extraordinary TDT inspection. PHS Magnum welds AlMg 5083/5754 aluminium (TIG) and 304L/316L stainless steel, performs steel passivation and provides full documentation for the trailer file. Typical time including documentation: 4-7 working days depending on scope.

Silo trailer tank welding — a specialist repair

Welding a pressure vessel after an accident is the most rigorous repair on a silo trailer. It requires: a certified welder, a WPS approved for the trailer, certified filler materials, NDT by an external laboratory, and an extraordinary TDT inspection.

PHS Magnum has the complete competence package: welders certified to ISO 9606-2 (aluminium) and ISO 9606-1 (stainless steel), the tools, the materials, the documentation, and coordination with TDT.

Materials most frequently welded

The choice of filler material, method and testing depends on the tank material. A quick overview:

Tank materialTypical brandsFiller wireMethodNDT
Aluminium AlMg 5083Spitzer, KässbohrerER5183TIG (141)PT
Aluminium AlMg 5754Feldbinder EUT aluER5356TIG (141)PT
Stainless steel 304LFeldbinder EUT inoxER308LTIG / MIGPT + passivation
Stainless steel 316LFeldbinder premiumER316LTIG / MIGPT + passivation
Structural steel S355frames, mountingsER70S-6MIG/MAG (135)MT

Details of procedures and parameters for each material below.

Aluminium AlMg 5083 (Spitzer, Kassbohrer)

  • AlMg alloy with Mn additive (3-4%)
  • Tensile strength Rm: 290-345 MPa
  • Welding wire: ER5183 (for 5083), ER5356 (universal AlMg)
  • Gas: Argon 4.6 (99.996% purity)
  • Method: TIG (141) with tungsten electrode
  • Preheat: 100-150°C for thicknesses >6 mm

Aluminium AlMg 5754 (Feldbinder EUT aluminium)

  • AlMg 3% alloy
  • Tensile strength Rm: 220-275 MPa
  • Wire: ER5356
  • Method and procedures as for 5083

Stainless steel 304L (Feldbinder EUT inox)

  • Composition: 18% Cr, 10% Ni, low carbon content
  • Wire: ER308L (typically) or 308LSi
  • Method: TIG (141) for 2-6 mm plates, MIG/MAG (135) for thicker
  • Gas: pure argon or argon+H2 (TIG), argon+2% O2 (MIG)
  • Passivation required after welding

Stainless steel 316L (Feldbinder EUT premium, chemicals)

  • Additional molybdenum (2-3%) — resistance to pitting corrosion
  • Wire: ER316L
  • Procedures identical to 304L

Structural steel S355 (frame, mountings)

  • Wire: ER70S-6 (low-carbon steel)
  • Method: MIG/MAG (135)
  • Gas: argon + 18% CO2

The WPS (Welding Procedure Specification)

Every welding repair on a pressure vessel is carried out in accordance with a WPS approved for the given trailer:

  • Base materials (of the tank) and filler materials (wire)
  • Welding method (TIG 141 / MIG-MAG 135)
  • Parameters (current, voltage, travel speed)
  • Shielding gas + flow rate (typically 8-15 L/min)
  • Welding position (PA, PB, PC…)
  • Preheating temperature
  • Welding sequence (for long seams)
  • Required NDT after the repair

A WPS is available for most Spitzer, Feldbinder and Kassbohrer trailer types — PHS Magnum coordinates with the manufacturer for non-standard configurations.

Non-destructive testing (NDT)

After every welding job on a pressure vessel — mandatory NDT.

MT (Magnetic Particle Testing)

For ferromagnetic steels. Sensitivity: cracks from 0.05 mm. Test duration: 30-60 min per weld.

PT (Penetrant Testing)

For stainless steel (paramagnetic) and aluminium. Duration: 60-90 min including penetrant drying.

RT (X-ray radiography)

The highest sensitivity, expensive and time-consuming. Used for:

  • Welds after plate section replacement (highest responsibility)
  • Welds inside the tank (hard to reach for MT/PT)
  • Certain trailer types that require RT under the manufacturer’s documentation

Performed by external NDT laboratories. Time: 1-3 days from dispatch of samples to the report.

Passivation of stainless steel

After welding stainless steel (304L, 316L) we perform passivation — rebuilding the Cr2O3 passive layer destroyed by the high welding temperatures.

Procedure:

  1. Grinding the welds to Ra ≤ 0.8 µm
  2. Cleaning with isopropyl alcohol
  3. Passivation with nitric acid HNO3 20-50% (30-60 min reaction)
  4. Rinsing with demineralised water
  5. Drying with compressed air
  6. Passivation report for the trailer file

TDT inspection after welding

Welding a pressure vessel = an extraordinary TDT inspection is required.

Procedure:

  1. Notification to TDT (Katowice regional office)
  2. Inspector’s visit to the PHS Magnum hall
  3. Visual inspection of the welds after the repair
  4. Verification of documentation (WPS, welder’s certificate, NDT report)
  5. Hydrostatic pressure test (1.5x working pressure)
  6. Issue of the extraordinary inspection certificate
  7. Date of the next periodic inspection

Time: 1 day. The certificate is issued on the spot after a passed inspection. If the vehicle comes to us after a failed TDT inspection, tank welding with complete documentation is most often the key item cleared from the inspection report.

Contact

Silo trailer service department: +48 602 716 551 TDT department (Roland Sobota, MSc Eng): +48 504 788 385 E-mail: biuro@magnumchorula.pl · base in Chorula near Opole, Poland, 4 km from the A4 junction

Related: Accident repairs (pillar) · Tank crack repair · Failed TDT — what next · TDT inspections of silo trailers

Frequently Asked Questions

Only a welder certified to ISO 9606 for the given material — PN-EN ISO 9606-2 for AlMg aluminium, PN-EN ISO 9606-1 for 304L/316L austenitic steel. Additionally, for a tank under TDT supervision a WPS (Welding Procedure Specification) approved for the trailer is required. Without both requirements, welding a pressure vessel is ILLEGAL.

Main methods: TIG (141) for AlMg 5083/5754 aluminium and stainless steel (thinner plates 2-6 mm), MIG/MAG (135) for thicker steel components. Pure argon (4.6) as the TIG shielding gas for aluminium, argon with additives for MIG. Wire: ER5183 for AlMg aluminium, ER308L/ER316L for stainless steel.

NDT (Non-Destructive Testing) is the non-destructive examination of welds. Required after every welding repair of a pressure vessel. Methods: MT (Magnetic Particle — ferromagnetic steel), PT (Penetrant — non-magnetic stainless steel and aluminium), RT (Radiography — for the highest-responsibility welds). Performed by certified external NDT laboratories.

Yes. Every welding job on a silo trailer pressure vessel requires an **extraordinary TDT inspection** after the repair. Procedure: notification to TDT, inspection of the welds by an inspector, hydrostatic pressure test, issue of a certificate allowing return to service. Without a TDT inspection after welding, the vehicle may not transport under pressure.

Yes, but aluminium demands more expertise than steel: preparation temperature (preheat 100-150°C for greater thicknesses), filler material selection (ER5183 for AlMg-5083, ER5356 for 5754), protection against contamination (aluminium reacts strongly with oxygen). PHS Magnum has TIG welders certified for aluminium.

Pure welding time depends on the weld length: minor micro-cracks 2-4 hours, longer cracks 4-8 hours, replacing a plate section 1-2 days. Plus external NDT (1-2 days' wait) + preparation for the TDT inspection (1 day) + the inspection itself (0.5 day). In total 4-7 working days depending on scope.

Yes, it is mandatory. Passivation with nitric acid (HNO3, 20-50%) over the weld area and the HAZ (Heat Affected Zone) — the high welding temperatures destroy the passive layer of stainless steel. Reaction time 30-60 min, rinsing with demineralised water, drying. We issue a passivation report for the trailer file.

Welding a pressure vessel under TDT supervision may only be done by welders certified to ISO 9606 for the given material, following an approved WPS, with mandatory NDT and an extraordinary TDT inspection. Without these elements the repair is illegal and the TDT inspector will not accept it. That is why we recommend having the welding done at a service centre with the full documentation.

A complete set goes into the trailer file: the welder's ISO 9606 certificate, the WPS for the given repair, filler material certificates, the NDT report from the external laboratory, the passivation report for stainless steel, and the extraordinary TDT inspection certificate. This set is essential at subsequent inspections and when selling the vehicle.

Not always. Minor cracks and micro-cracks can often be welded without replacing a section. Replacing a plate section is necessary for extensive denting, perforation, or corrosion exceeding the permissible wall thickness. We determine the scope after inspection and wall thickness measurement — see also our [accident repairs of silo trailers](/en/service/silo-trailers/accident-repair/).

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 the A4 Motorway

180 km from German border

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