AKO Membrane Pinch Valves

Introduction

Membrane pinch valves are an alternative to butterfly and ball valves in the discharge line of Feldbinder silo trailers. Instead of a rotating disc or ball, flow shut-off is achieved by a flexible internal membrane — a wear component that presses against the pipe bore and seals it completely. In the fixed horizontal EUT configuration, the pinch valve controls the flow of granulate or bulk cement during pneumatic discharge; in the tipping KIP silo, it operates under pressure while the tank is raised. In both applications, service life is determined not by the body but by the condition of the membrane.

AKO pinch valves have an aluminium body and flange with a black NBR sleeve, manufactured to DIN 28460. They are flanged assemblies — connected to the pipework via a PN 10/16 flange — so both bore size and flange pattern must match when ordering. In PHS Magnum’s service experience, the internal membrane is one of the most frequently replaced components: it cracks, hardens, or delaminates after many cycles of contact with bulk material, and replacement restores a tight seal without touching the valve body. For Feldbinder silo trailers we stock membranes in DN80 and DN100, and we also carry the sister Prokosch membrane system — valves and membranes — so we can supply a compatible part regardless of which system is already fitted to the trailer.

We hold stock of AKO pinch valves, internal membranes, and Prokosch components at Chorula near Opole.

Specification and Materials

AKO membrane pinch valves:

The internal membrane is a separately available wear item, supplied for every valve type.

Flange Dimension Table

Flange dimensions must match the connection on the trailer’s discharge pipework. DN100 is available in two versions (TW3 and PN 10/16), which differ in bolt circle and hole diameter. Please confirm the flange version on the vehicle before ordering.

Sizes and Types

Internal membranes are available for every valve type in the following bore sizes:

• DN80
• DN100

We also stock the sister Prokosch membrane system — valves and membranes — allowing us to supply a compatible component regardless of which membrane system is fitted to a given Feldbinder silo trailer.

Compatibility with Feldbinder Silo Trailers (EUT/KIP)

• EUT — the membrane pinch valve cuts off and regulates material flow during pneumatic discharge from the fixed horizontal tank. Selected by bore (DN80/DN100) and flange connection DIN 28460, PN 10/16.
• KIP — in the tipping silo, the pinch valve operates under pressure while the tank is raised; the internal membrane is subject to higher stress here and should be inspected at every service interval.

Components are selected by bore and flange connection, not by Feldbinder trailer type. For Prokosch systems we supply the equivalent from that product line. In practice, if a Feldbinder silo trailer is fitted with AKO pinch valves throughout, it makes sense to maintain a single consistent system along the entire discharge line — it simplifies membrane stock management and reduces service complexity. Where mixed AKO and Prokosch systems have been fitted over a trailer’s history, we can rationalise the line during a full refurbishment.

Common Issues on Feldbinder Silo Trailers

From PHS Magnum’s service experience with Feldbinder trailers:

• Leaking in the closed position — cracked, hardened, or delaminated internal membrane; membrane replacement restores the seal without replacing the valve body.
• NBR sleeve hardening — loss of elasticity over time; presents as poor valve closure.
• Mismatched flange pattern — incorrect bolt circle or hole diameter for the pipework; always verify flange dimensions before ordering.
• System mix-up — an AKO membrane will not fit a Prokosch pinch valve and vice versa; the system fitted to the trailer must be identified at the time of ordering.

On Feldbinder silo trailers, where the valve specification permits, membranes and sleeves can be sourced in materials with enhanced chemical resistance for specific bulk media — we confirm the appropriate grade for each valve type. The standard for the AKO pinch valve described here remains the black NBR sleeve.

The membrane pinch valve offers one practical advantage for silo trailer operators: mechanical simplicity. The absence of a rotating ball or disc means fewer moving parts susceptible to seizing, and replacing the internal membrane is a quick operation that does not require removing the entire valve assembly from the pipework, provided service access has been maintained. Keeping a stock of DN80 and DN100 membranes on the trailer or at the depot allows a typical seal failure to be rectified immediately, without waiting for a replacement valve body.

Availability and Delivery

We stock AKO pinch valves, DN80/DN100 internal membranes, and Prokosch system components at Chorula near Opole (4 km from the A4 motorway, approximately 180 km from the German border).

Courier delivery within Poland and the EU; combined orders with other pipework components are welcome. For availability and pricing — ask for a quote. Membrane replacement and discharge-line overhaul are also carried out as part of the PHS Magnum silo trailer service, including during TDT inspections.

Related Categories

• Ebro Butterfly Valves — Ebro butterfly valves, black and white Perbunan versions.
• Other Butterfly Valves — Burgmer and Kraft valves with accessories.
• Prokosch Product Ball Valves — Prokosch system product ball valves.
• Ball Valve Seals — seal kits for DN80/DN100 ball valves.
• See also: spare parts catalogue, PHS Magnum silo trailer service, pasternak.me.

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, internal ISO 9001:2015 auditor (DEKRA).