Ball Valve Puff Insert for Spitzer SF/SK Silo Trailers
The puff insert works together with the product ball valve in the discharge assembly of an aluminium Spitzer silo trailer (SF and SK series). It facilitates controlled flow of bulk material through the system, operating as a matched pair with the product ball valve of the same type and size. As a component working under pressure and in direct contact with the conveyed medium, the puff insert must be correctly matched — both in terms of material and dimensions — to the rest of the discharge assembly.
We supply puff inserts in DN80 or DN100, for Prokosch or ZR type valves. The body is cast iron, with a Desmopan seal, steel ring and NBR outer seal. With standardisation across two sizes and two types, selecting the correct puff insert for any Spitzer silo trailer product valve is straightforward and repeatable.
For fleets in continuous operation, ready-to-fit kits are particularly convenient: a factory-assembled product ball valve supplied with the matching puff insert (Prokosch or ZR). These kits eliminate any risk of component mismatch and reduce installation time for the entire discharge assembly. The puff insert should be serviced and replaced together with the product valve and ball seal kit.
The material specification of the puff insert corresponds to the operating conditions of the product assembly. The cast iron body provides mechanical robustness; the Desmopan seal is selected for compatibility with the conveyed medium and working pressure; the steel ring stabilises the component; and the outer NBR seal protects the interface with the rest of the valve assembly. This specification is consistent with the Prokosch (Type 420) and ZR product ball valves for which these puff inserts are designed, in the standard DN80 and DN100 sizes.
Specification and Materials
| Parameter | Value |
|---|---|
| Body material | Cast iron |
| Seal | Desmopan |
| Ring | Steel |
| Outer seal | NBR |
| Compatible with | Prokosch or ZR type product ball valves |
Sizes and Types
| Size DN (mm) | Type |
|---|---|
| DN80 | Prokosch, ZR |
| DN100 | Prokosch, ZR |
Ready-to-fit kits also available: factory-assembled product ball valve + matching puff insert (Prokosch or ZR).
Compatibility with Spitzer Silo Trailers (SF/SK)
The puff insert must be matched to the product ball valve of the same type (Prokosch or ZR) and size (DN80 or DN100) in Spitzer SF and SK silo trailers. When assembling or reconditioning a discharge assembly, the safest solution is a ready-to-fit valve + puff insert kit, with both components factory-matched to one another.
Given that the puff insert operates under pressure and in contact with bulk material, its material selection (cast iron) and seals (Desmopan, NBR) are suited to the conditions of pneumatic discharge in silo trailers. When servicing the product assembly, the condition of the valve, puff insert and ball seals should be inspected simultaneously.
Common Failure Modes on Spitzer Silo Trailers
In service practice, the most common issue is wear of the Desmopan or outer NBR seal in the puff insert, leading to leaks in the discharge assembly. Another frequent problem is build-up of bulk material and corrosion of the cast iron body when maintenance is neglected, which restricts the movement of the component.
Because the puff insert operates as a pair with the product valve, failures in one component often present alongside problems with the other. When diagnosing a discharge leak or restricted unloading, the entire assembly should be inspected — and when replacing parts, a ready-to-fit valve + puff insert kit matched to the correct Prokosch or ZR type and DN80/DN100 size is worth considering.
In workshop practice, the most reliable way to avoid recurring problems is to service the discharge assembly as a complete unit: the product ball valve, its ball seals (PTFE + NBR kit) and the puff insert. All components are selected to the same type (Prokosch or ZR) and size (DN80 or DN100), so after replacement they operate together as a factory-matched system. A ready-to-fit valve + puff insert kit also eliminates the risk of selection errors and reduces on-vehicle installation time.
Availability and Delivery
Puff inserts in DN80 and DN100 for Prokosch and ZR types, as well as ready-to-fit valve + puff insert kits, are dispatched from the PHS Magnum warehouse in Chorula near Opole, and via direct delivery.
- Poland — courier delivery
- DACH — delivery to Germany, Austria and the Czech Republic
- Collection — PHS Magnum warehouse, Chorula near Opole, 4 km from the A4 motorway
For parts selection or ready-to-fit kit enquiries: Spitzer service team, tel. +48 602 716 551. Full range of services: magnumchorula.pl/en/service/.
Related Categories
- Prokosch Product Ball Valves — aluminium product ball valves, Prokosch type (Type 420) and ZR
- Segmented Ball Valves — segmented air ball valves, ZR type (Type 500)
- Ball Seals — ball seal kits (PTFE + NBR)
- Spitzer Spare Parts Catalogue — full category overview
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).
