AKO Pinch Valves in Spitzer SF/SK Silo Trailers
AKO pinch valves are shut-off valves in which the flow of bulk material is stopped by compressing a flexible elastomeric sleeve (membrane) inside the body. In aluminium Spitzer SF and SK silo trailers they are used wherever a full, gentle shut-off of the flow channel is required without a metal disc or ball sitting in the flow path. The design is valued for its simplicity and clean material cut-off.
We supply AKO pinch valves with an aluminium body and flange and a black NBR sleeve, to DIN 28460. AKO membranes are also available as a separate spare part — inner membranes in DN80 and DN100. This means a worn sleeve can be replaced without changing the entire valve body, reducing both downtime and repair cost.
For fleets with mixed valve systems, we also carry the sister membrane system from Prokosch — both valves and membranes. This allows consistent spare-part sourcing across a Spitzer silo trailer fleet, regardless of whether the original AKO system or a Prokosch equivalent is fitted.
The operating principle of a pinch valve differs fundamentally from a butterfly or ball valve. There is no rigid mechanical element in the flow path — shut-off is achieved purely by compressing the flexible sleeve. This provides a clean, full closure and reduces the tendency for bulk material to jam the valve in the open position, which can be an advantage with materials prone to bridging or build-up. The only wear part is the NBR sleeve itself, which is why we offer it as a separate spare — inner membranes in DN80 and DN100 — making valve servicing both quick and cost-effective.
Specification and Materials
| Parameter | Value |
|---|---|
| Body | Aluminium |
| Flange | Aluminium |
| Sleeve (membrane) | Black NBR |
| Standard | DIN 28460 |
| Inner membranes | DN80, DN100 |
| Sister system | Prokosch (valves and membranes) |
Sizes and Types
AKO pinch valves are selected by DN size, flange standard, bolt-circle diameter, and bolt-hole diameter:
| DN size (mm) | Flange standard | Bolt circle (mm) | Bolt hole dia. (mm) | Length (mm) |
|---|---|---|---|---|
| DN80 | PN 10/16 | 160 | 18 | 226 |
| DN100 | TW3 | 150 | 14 | 282 |
| DN100 | PN 10/16 | 180 | 18 | 282 |
DN100 is available in two flange configurations (TW3 and PN 10/16), differing in bolt-circle diameter and bolt-hole size — the correct version must match the connection on the specific trailer. Inner membranes (spare parts) are available in DN80 and DN100.
Compatibility with Spitzer Silo Trailers (SF/SK)
AKO pinch valves are selected to match the diameter and flange of the discharge connection on Spitzer SF and SK silo trailers, in accordance with DIN 28460. Inner membranes in DN80 and DN100 cover the typical membrane valve requirements for these vehicles.
For fleets where some trailers are fitted with the Prokosch system, we supply the sister pinch valves and membranes — allowing a service technician to source all membrane components for the entire fleet from a single supplier. The choice between the AKO and Prokosch systems depends on what is actually installed in the trailer.
Common Faults in Spitzer Silo Trailers
In practice, the most frequent issue with a pinch valve is wear of the NBR sleeve — cracking, hardening, or abrasion causes the valve to lose its sealing ability. Replacing just the inner membrane (DN80 or DN100) normally restores full function without replacing the entire valve assembly.
A second common issue is bulk material build-up inside the valve bore, and corrosion of the aluminium body and flange where maintenance has been neglected. With flanged installations it is also important to check the condition of the interflange gaskets and to ensure even bolt torque — uneven clamping can distort the flange face and cause a leak that is easily mistaken for sleeve wear.
In service experience, sleeve life depends on the nature of the material being carried: more abrasive loads accelerate wear, while gentle granulates extend the interval between replacements. For this reason, the inner membrane should be treated as a consumable item and inspected at each periodic service — cracking, hardening, or visible abrasion of the NBR sleeve is the signal to replace it before a sealing failure occurs mid-discharge. Keeping DN80 and DN100 membranes in stock means they can be changed immediately, without a parts order and without replacing the entire valve body.
Selection and Service Considerations for Spitzer SF/SK Silo Trailers
In aluminium Spitzer SF and SK silo trailers, AKO pinch valves are typically specified where the designer chose to avoid a disc in the flow path — particularly with materials prone to build-up, where a smooth, gentle closure reduces the risk of material bridging. For Spitzer SF/SK service work this has a practical consequence: since the only moving part is the sleeve, diagnosis of the valve comes down to assessing the membrane condition rather than investigating complex mechanics. When refurbishing the discharge line of a Spitzer silo trailer, this is usually the quickest node to restore — replacing a DN80 or DN100 insert rather than the entire valve body.
A further observation from SF/SK operation is the sensitivity of the flanged joint: with an aluminium body and flange, uneven bolt torque can distort the mating faces and cause a leak that is easy to confuse with sleeve wear. For this reason, when servicing AKO valves on Spitzer trailers we always begin by checking for even clamping and inspecting the interflange gaskets before reaching for a new membrane. Where a Spitzer fleet has mixed AKO and Prokosch systems, we can help standardise the discharge line to a single solution, simplifying stock management for spare membranes across the whole fleet.
Availability and Delivery
AKO pinch valves and DN80/DN100 inner membranes are dispatched from PHS Magnum’s warehouse in Chorula near Opole and are also available via direct delivery. The sister Prokosch system (valves and membranes) is available to order.
- Poland — courier delivery
- DACH — delivery to Germany, Austria, and Czech Republic
- Collection — warehouse in Chorula near Opole, 4 km from the A4 motorway
For valve and membrane selection to suit your installation, contact our Spitzer service team on +48 602 716 551. Full range of services: magnumchorula.pl/en/service/.
Related Categories
- Ebro Butterfly Valves — Ebro butterfly valves, aluminium body, Perbunan
- Other Butterfly Valves — Burgmer and Kraft butterfly valves with accessories
- Gestra RV Check Valves — wafer-style check valves type RV
- Spitzer Spare Parts Catalogue — full category overview
See also: This category in the full PHS Magnum network catalogue (all makes) →
Author: Aleksy Pasternak — Managing Partner PHS Magnum, 20 years in the industry, ISO 9001:2015 internal auditor (DEKRA).
