At a glance
Silo trailer frame straightening after an accident is done on a hydraulic press with geometry control on a measuring station. Light deformations (up to 50 mm) are straightened cold, medium ones (50-100 mm) with local heating, and for damage above 100 mm or cracked main welds we replace the frame section. After the repair we issue a geometry report. Disturbing the pressure vessel mountings requires notification to TDT. We handle steel and aluminium frames.
Silo trailer frame straightening — key points
The silo trailer frame is the load-bearing structure that transfers the mass of the tank and its load (30+ tonnes) to the chassis. After an accident the frame can be deformed in a way that is not visible to the naked eye, yet affects the safety and geometry of the whole rig.
PHS Magnum straightens silo trailer frames across the full range — from minor deformations to major structural repairs.
Workshop equipment
Hydraulic press
A straightening station with a hydraulic press up to 200 tonnes. It allows:
- Straightening of deformed longitudinal members
- Levelling of cross-members
- Repair of distorted load-bearing profiles
- Correction of fifth-wheel and coupling mounts
Measuring station
Geometry is checked after straightening — dimensions measured against the frame’s reference points in accordance with the manufacturer’s documentation.
Structural welding
For heavier repairs — MIG/MAG welding (steel, ISO 9606-1) or TIG (aluminium, ISO 9606-2) by certified welders.
Frame straightening procedure
1. Initial diagnostics
- Visual inspection of the entire frame with photo documentation
- Geometry measurement in the current state
- Identification of critical points (cracked welds, structural deformations)
- Technical assessment: straighten or replace the section?
2. Removal of obstructing components
Before straightening we remove components that could restrict access or get damaged:
- Electrical equipment (lighting, sensors)
- Auxiliary pneumatics (near the area being straightened)
- Protective covers
3. Straightening
- Light deformations (up to 50 mm) — cold straightening on the press
- Medium (50-100 mm) — controlled local heating (steel max 400°C, aluminium max 150°C) + straightening
- Severe (>100 mm or structural damage) — cutting out the deformed section and welding in a new one
4. Geometry measurement after the repair
Measuring station — control of critical dimensions:
- Axle spacing (tolerance ±3 mm)
- Parallelism of the longitudinal members
- Fifth-wheel height
- King pin angle — ±1°
5. Repair report
Documentation for the vehicle file:
- State before repair (photographs, measurements)
- Work performed
- State after repair (photographs, measurements)
- Welder’s / mechanic’s signature
When straightening is not enough
Replacing a frame section instead of straightening is the right choice for:
- Cracked main welds — straightening will not restore the weld’s strength
- Deformations above 100 mm — the material has lost its properties
- Structural corrosion in the deformation area — straightening + corrosion = accelerated failure
- Repeated deformations of the same section — material fatigue
Section replacement requires: a certified welder, materials compliant with the manufacturer’s specification, and TDT documentation (if the section lies in the tank mounting area).
Deformation range vs method and repair time
The table matches the straightening method and indicative lead time to the scale of deformation. These are indicative values — the final scope is set after geometry measurement.
| Deformation range | Method | Lead time | TDT requirement |
|---|---|---|---|
| up to 50 mm | cold straightening on the press | 1-2 working days | no, if tank mountings untouched |
| 50-100 mm | local heating + straightening | 3-5 days | as above |
| over 100 mm | cutting out and replacing the section | 5-10 days | yes, if the section is in the tank mounting area |
| full repair with profile replacement | structural welding | up to 15 days | yes, when mountings are involved |
| geometry measurement + report | measuring station | + 0.5-1 day | — |
The frame material affects the procedure: steel is locally heated to a maximum of 400°C, aluminium to 150°C with thermocouple control. Structural welding is done MIG/MAG for steel (ISO 9606-1) and TIG for aluminium (ISO 9606-2) by certified welders.
Frame straightening is often combined with other accident repairs: axle replacement, tank welding and paint renovation. When the tank mountings have been disturbed, the integrity check is carried out as part of the preparation for the TDT inspection of silo trailers.
Contact
Tel: +48 602 716 551 Email: biuro@magnumchorula.pl ul. Kościelna 9, 47-316 Chorula, Poland
