One catalogue for many silo trailer brands
A product ball valve is the valve gear that shuts off the flow of bulk material at the discharge outlet of a silo trailer. Unlike air valves, it works in direct contact with the product — PE/PP granulate, flours and powders pass through it — so its ball and seals are selected for abrasion, not for a clean air stream. A sound product valve determines positive shut-off and controlled outflow during discharge, and its tightness in the closed position protects the purity of the loads carried.
PHS Magnum has been servicing silo trailer fleets of various brands since 1990, which is why we match parts not by a stretched “compatibility with one manufacturer” but by the real mounting parameters: DN size and flange standard. This is exactly why one catalogue of product ball valves covers trailers from different European factories — from Spitzer through Feldbinder to Kässbohrer and other manufacturers. Standardisation on two diameters, DN80 and DN100, and a flange to the DIN 28460 standard makes part selection for a specific outlet point repeatable regardless of the trailer brand.
Our range includes aluminium product ball valves Type Prokosch (Type 420) and the sister design type ZR with a stainless steel ball. Full catalogue of parts categories: /en/czesci-zamienne/, and the range of service work: magnumchorula.pl/serwis/.
Technical specification
Type Prokosch (Type 420) is aluminium outlet valve gear with a flange standardised to DIN 28460. Below are the parameters of both versions — with a chrome-plated cast iron ball (Prokosch 420) and the sister type ZR with a stainless steel ball:
| Parameter | Type Prokosch (Type 420) | Type ZR (sister design) |
|---|---|---|
| Body material | aluminium or cast iron | aluminium or cast iron |
| Ball material | chrome-plated cast iron | stainless steel |
| Ball seal | PTFE (Teflon) | PTFE (Teflon) |
| Body gasket | NBR | NBR |
| Working pressure | 10 bar | 10 bar |
| Temperature range | -25°C to 90°C | -25°C to 90°C |
| Flange standard | DIN 28460 | DIN 28460 |
| DN sizes | DN80, DN100 | DN80, DN100 |
The choice of body material — aluminium or cast iron — follows from the loading of the outlet point and weight requirements: aluminium is lighter, cast iron mechanically stronger. The chrome-plated cast iron ball combines hardness with abrasion resistance, which matters because bulk material flows through the product valve. The PTFE ball seal gives low turning resistance and reliable closure of the outlet, while the NBR body gasket seals the flange connection. Type ZR with the stainless steel ball extends the range of applications where chrome-plated cast iron is not enough — with more demanding media or elevated requirements.
Each of the valves — Type Prokosch (Type 420) and type ZR — is offered in DN80 and DN100.
In operating practice, a product ball valve wears above all on the ball surface and in the PTFE ball seal — those are what the abrasive stream of bulk material flows through. The symptoms of wear are leakage in the closed position (product escaping or trickling through at the customer’s site) and increasing lever turning resistance. On DN80 and DN100 valves the typical repair is replacing the complete set of ball seals (PTFE + NBR kit) without removing the whole valve gear from the outlet point; with a damaged ball or body, the valve is replaced as a whole. We make the “repair or replace” decision after inspection — we do not quote made-up service life figures, because the interval depends on the medium, the intensity of operation and whether the valve works together with a blow unit.
Compatibility with silo trailer brands
Because the product ball valve is mounted on the discharge outlet and selection depends on the DN size and flange standard rather than the logo on the tank, the same Type Prokosch (Type 420) / type ZR catalogue in DN80 and DN100 covers silo trailers from many manufacturers:
- Spitzer — SF (non-tipping) and SK (tipping) series. Brand-side details and selection: see the Spitzer portal below.
- Feldbinder — EUT (horizontal non-tipping tank) and KIP (tipping pressure silo, Kippsilo) series. Details: see the Feldbinder portal below.
- Kässbohrer — K.SSK and K.SSL silo trailers.
- Other European manufacturers — silo trailers with an outlet point using the DIN 28460 flange standard, in DN80 or DN100.
The DIN 28460 flange guarantees that a valve of the given diameter fits the outlet installation dimensionally and can be swapped without modifications. When ordering, please state the DN size, the valve type (Prokosch or ZR) and — if a blow unit is to be replaced at the same time — information about the whole point, which lets us assemble a matching valve + blow unit + seals set without mixing components of different systems.
Warehouse in Chorula near Opole
We supply product ball valves Type Prokosch (Type 420) and the sister type ZR in DN80 and DN100 from the PHS Magnum warehouse in Chorula near Opole, 4 km from the A4. We build the stock around what actually moves in servicing multi-brand fleets — not the manufacturer’s full catalogue — so typical DN80/DN100 items are usually available off the shelf, while non-typical configurations (e.g. type ZR with the stainless steel ball) are fulfilled via direct supply. Alongside the valves we match complementary DN80/DN100 blow units and ball seal kits (PTFE + NBR), which lets you service the entire product shut-off point from a single source.
- Poland — courier shipping
- EU — delivery to European Union countries (including Germany, Austria, the Czech Republic)
- Collection in person — Chorula warehouse near Opole, 4 km from the A4
Selection of the valve, ball material and complete seal set is handled by the PHS Magnum service, tel. +48 602 716 551.
Selecting parts for mixed-brand fleets
A product ball valve is mounted on the discharge outlet, so in a mixed fleet its selection is decided by the DN size and flange standard, not the tank brand. Differences between designs do appear, however, in how many such valves a given trailer has and how they work. In Spitzer SF/SK aluminium tanks the product valve terminates the outlet point, and the choice between a chrome-plated cast iron ball (Prokosch Type 420) and a stainless steel one (type ZR) is tied above all to the abrasiveness of the material carried. In Feldbinder EUT horizontal tanks with bottom outlets, a valve terminates every discharge outlet — in multi-chamber versions there are as many as there are chambers, so during a refurbishment they are inventoried chamber by chamber. In the tipping KIP silo the outlet works under pressure with the load inclined, so positive closure and the tightness of the PTFE ball seal have practical significance here. On Kässbohrer K.SSK/K.SSL silo trailers the selection principle stays the same — diameter and flange, not the logo.
By comparison: thanks to standardisation on DN80 and DN100 and the DIN 28460 flange, the same valve can be swapped without modifications on the outlet of a trailer of any of these brands. For a mixed fleet this means one material decision (chrome-plated cast iron versus stainless steel) repeated across different designs, instead of separate catalogues for each manufacturer.
The role of the central warehouse in the network
The central warehouse in Chorula lets you service the product shut-off point from a single source regardless of whose factory the trailer came from. Typical DN80/DN100 items are kept off the shelf, while non-typical configurations — including type ZR with the stainless steel ball — are fulfilled via direct supply. We match complementary DN80/DN100 blow units and ball seal kits (PTFE + NBR), so the entire outlet point can be assembled without mixing components of different systems. For a fleet combining several brands, one enquiry can cover the outlets of trailers from different manufacturers at once, because selection comes down to the diameter and flange anyway.
What to watch for across brands
- Number of outlets — multi-chamber horizontal tanks have as many product valves as chambers; wear is checked for each outlet separately.
- Ball material for the medium — with more abrasive materials or elevated requirements, consider type ZR with a stainless steel ball instead of chrome-plated cast iron.
- Operation under inclination — in tipping silos, positive closure of the outlet counts most, because the load flows down under pressure; it pays to check the PTFE ball seal.
- Swapping without modifications — the DIN 28460 flange means a valve of the given diameter can be swapped on the outlet of a trailer of any brand without touching the rest of the valve gear.
- The complete point from one source — with a planned replacement it pays to select the valve, blow unit and seal kit together, to avoid mixing components of different systems.
- Repair versus replacement — with worn ball seals the PTFE + NBR kit is often enough; only a damaged ball or body justifies replacing the whole valve.
- Weight versus strength — the choice of aluminium or cast iron body is matched to the loading of the outlet point and weight requirements, the same for every brand we support.
- One item for a mixed fleet — with a fleet combining Spitzer SF/SK, Feldbinder EUT/KIP and Kässbohrer K.SSK/K.SSL, standardising the flange and diameter lets you keep one valve index instead of a separate item per brand.
- Identification by outlet, not by logo — the unit is selected by the outlet diameter, flange and medium read from the vehicle, which distinguishes the hub’s cross-brand approach from single-brand catalogues.
Specialist brand portals
Selection of parts for a specific silo trailer brand and series is handled by our dedicated portals:
- Spitzer (SF/SK) — Prokosch product ball valves on spitzer.pl
- Feldbinder (EUT/KIP) — Prokosch product ball valves on feldbinder.pl
Related categories
- Segmented ball valves — segmented air ball valves type ZR (Type 500)
- PTFE ball valves — air ball valves with PTFE seals
- Ball valve blow units — DN80/DN100 blow units for Prokosch and ZR valves
- Ball seals — ball seal kits (PTFE + NBR)
- Full catalogue: /en/czesci-zamienne/
Author: Aleksy Pasternak — Managing Partner at PHS Magnum, 20 years in the industry, internal auditor ISO 9001:2015 (DEKRA).
