Introduction
The rear hatch of a Feldbinder silo trailer — the rear manhole — is the inspection and discharge opening at the back of the tank. Although it is opened less frequently than the filling hatch, it must seal just as reliably, because it operates under the same working pressure as the rest of the silo. The seal is provided by the rear hatch gasket, which is pressed against the hatch seat by the closing mechanism.
On the EUT (horizontal, fixed-tank silo trailer), a leaking rear hatch reduces the efficiency of pneumatic discharge and, in food-grade variants, risks contaminating the cargo. On the KIP (tipping silo), the rear hatch faces the additional stress of the tank tilting to 45–50° — the seal must hold at working pressure both in transport position and when tipped for assisted pressurised discharge. For this reason, the rear hatch gasket is treated as a controlled element: checked at every service and replaced at the first signs of lost elasticity.
PHS Magnum in Chorula near Opole holds a stock of rear hatch and manhole gaskets for Feldbinder silos and other brands.
Specification and Materials
We supply gaskets for rear hatches across a wide range of silo trailer manufacturers. Gasket material and dimensions are selected to match the hatch type on the specific trailer and the intended application (industrial or food-grade) — the seat geometry and seal profile are unique to each design and cannot be reduced to a single universal dimension.
Where required, we will select a gasket that is materially consistent with the other food-grade seals on an EUT trailer.
Sizes and Types
Rear hatch gaskets are selected to the type and geometry of the specific hatch. Our range covers silos including:
- Feldbinder
- Spitzer (silo side and hatch)
- Kassbohrer (new and old type)
- and others
For Feldbinder silo trailers, selection is based on the rear hatch/manhole type on the individual trailer.
Compatibility with Feldbinder Silo Trailers (EUT/KIP)
- EUT — the gasket seals the rear inspection/discharge hatch of the horizontal fixed tank; integrity is critical for pneumatic discharge efficiency and cargo cleanliness in food-grade applications.
- KIP — the same rear hatch seal on a tipping silo; the closure must maintain integrity during tipping and pressurised discharge.
Gaskets are selected to the geometry of the specific rear hatch on the Feldbinder trailer; we can help identify the correct component.
Interaction with the Rear Hatch Closing System
The rear hatch gasket works in conjunction with the hatch closing mechanism — on tipping silos (KIP) this typically comprises a handle, an eye-cross bolt, and a spring maintaining closing pressure. A reliable seal requires both elements to be in good condition:
- Gasket — creates the sealing contact; if it hardens or permanently deforms, the hatch will leak regardless of how tightly it is closed.
- Closing system — provides and maintains the clamping force; a weakened spring or corroded bolt reduces pressure on the gasket.
On the KIP there is an additional challenge: the tank tilts to 45–50°, so the rear hatch closure must remain sealed outside the transport position. This places higher demands on the gasket than a fixed hatch. For this reason, rear hatch servicing always covers both the gasket and the closing mechanism together. We supply gaskets for a wide range of hatch designs (including Feldbinder, Spitzer, Kassbohrer new and old type), selecting material to suit the trailer’s application — with full compliance with hygiene requirements for food-grade EUT operations.
Common Issues
- Hardening and cracking — an over-dried gasket no longer seals the hatch; replace immediately.
- Permanent compression set — a gasket held under prolonged load loses its profile; replace with new.
- Confusion with a filling hatch gasket — different geometry; a dedicated rear hatch gasket must be used.
- Wrong material in food-grade service — seals in contact with cargo on a food-grade EUT must meet hygiene requirements.
Availability and Delivery
Our rear hatch gasket stock is held in Chorula near Opole (4 km from the A4 motorway, approximately 180 km from the German border). Common types are usually available from stock; others are sourced to order.
Courier delivery within Poland and across the EU; combined orders with the rear hatch closing hardware and filling hatch gaskets are welcome. For selection advice and pricing — ask for a quote.
Related Categories
- Rear Hatch Closing Bolts — Closing bolts for the rear inspection hatch of Feldbinder KIP silos.
- Loading Hatch Gaskets — Elastomer seals for the top loading hatches of Feldbinder silos.
- Flange Gaskets — EPDM/NBR/Elapac flange gaskets.
- Feldbinder KIP Parts — hydraulics and seals for the tipping KIP silo.
- See also: spare parts hub, silo trailer service at 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).
