Introduction
The rear hatch of a silo trailer seals the back of the tank — and it must do so reliably, especially in tipping silo designs. Within the Feldbinder range, the tipping model is the KIP (Kippsilo): the silo is raised hydraulically to 45–50°, with pneumatic discharge assisted by the tilt. In this configuration, the rear hatch operates under working pressure and at a varying angle, so its closing mechanism must be absolutely dependable.
The rear hatch closing system is not a single bolt — it is a set of co-operating components: a closing handle, an eye-cross bolt, and a spring that maintains clamping force. The stainless steel spring ensures the seal does not lose tension under vibration or changes in tank angle. From a Feldbinder service perspective, a securely closing rear hatch is a prerequisite for both the integrity of the seal and the safety of the discharge — a loose or worn mechanism risks a pressurised hatch leak.
PHS Magnum in Chorula near Opole supplies the complete, universal rear hatch closing system for tipping silo trailers.
Specification and materials
The complete, universal closing system for the rear hatch of a silo trailer includes:
| Component | Material | Dimension |
|---|---|---|
| Handle | Galvanised steel | M20 thread |
| Eye-cross bolt for handle | Galvanised steel | M20×110, 18 mm eye |
| Spring for eye bolt | Stainless steel | — |
Galvanised steel provides corrosion resistance against road salt for the handle and bolt, while the stainless steel spring maintains reliable clamping force despite vibration and moisture.
Dimensions and types
The system is supplied as a universal rear hatch closing set. Key dimensions:
- Handle — M20 thread
- Eye-cross bolt — M20×110, 18 mm eye
- Spring — stainless steel
For a specific rear hatch, fitment is confirmed against the dimensions on the trailer.
Compatibility with Feldbinder silo trailers (EUT / KIP)
- KIP (Kippsilo — tipping/raised silo) — the rear hatch closing system applies directly to raised-silo designs; secure clamping is critical during tilting and pneumatic discharge.
- EUT (horizontal silo trailer) — for component selection on a specific trailer’s rear hatch, we confirm the dimensions; the set is described as universal for tipping silo designs.
Final component selection is always based on the actual rear hatch dimensions of the Feldbinder trailer.
Why this is a system, not a single bolt
The rear hatch of a tipping silo closes differently from a conventional hatch — which is why the manufacturer specifies a complete closing mechanism rather than a single bolt. Three components work together:
- Handle (M20) — the operating element used to close the hatch.
- Eye-cross bolt (M20×110, 18 mm eye) — transfers clamping force to the cover.
- Spring (stainless steel) — maintains closing tension despite vibration and changes in tank angle.
The spring is the critical element. In the KIP, the tank tilts to 45–50°, and the rear hatch must remain securely closed in positions other than the transport position. Without a spring maintaining clamping pressure, bolt torque alone is insufficient to resist loosening. This is why we supply the system as a complete set — replacing a single worn component (most commonly the spring) restores the full integrity of the closing mechanism. Fitment is confirmed against the rear hatch dimensions of the specific Feldbinder trailer.
Common failure modes
- Fatigued spring — loss of tension reduces closing force; replace the stainless steel spring.
- Corroded handle or bolt — damaged zinc coating in road-salt conditions makes the hatch difficult to close; replace the affected component.
- Worn 18 mm eye — a worn eye prevents secure tightening.
- Incomplete set — a missing component (handle, bolt, or spring) reduces closing reliability; we supply the complete set.
Availability and delivery
The rear hatch closing system is stocked at our warehouse in Chorula near Opole (4 km from the A4 motorway, approx. 180 km from the German border). Complete sets are generally available; fitment to a specific hatch is confirmed after dimensional verification.
Courier delivery throughout Poland and the EU; combined orders with rear hatch seals are possible. For pricing, please ask for a quote.
Related categories
- Fill hatch bolts — complete butterfly bolts for upper fill hatches.
- Rear hatch seals — rear hatch gaskets for Feldbinder silo trailers.
- Feldbinder KIP parts — hydraulics and seals for the tipping silo.
- Feldbinder EUT parts — full range of spare parts for the EUT horizontal silo trailer.
- See also: spare parts hub, silo trailer service — PHS Magnum.
See also: This category in the full PHS Magnum network catalogue (all brands) →
Author: Aleksy Pasternak — Managing Partner PHS Magnum, 20 years in the industry, ISO 9001:2015 internal auditor (DEKRA).
