PTFE Ball Valves

PTFE Ball Valves in Spitzer SF/SK Silo Trailers

Air ball valves control compressed air flow within the pneumatic system of Spitzer aluminium silo trailers, series SF and SK. Operated with a quarter-turn of the handle and fitted with a PTFE-sealed ball, they provide fast, leak-free isolation or opening of the air circuit. In day-to-day operation — where the driver repeatedly switches pneumatic circuits during discharge — reliability and low operating resistance are essential.

We stock PTFE-sealed air ball valves in both standard and stainless versions. The body is nickel-plated brass, the ball is chrome steel, and the seal is PTFE, giving an operating range of -40°C to 120°C. These valves do not include a handle lock and are selected by DN size, internal thread size, body length, and working pressure.

For applications demanding higher pressure ratings or resistance to aggressive media, we also carry a heavy-duty V4A stainless steel version as a permanent direct-supply item — rated to 63 bar and 180°C. This means a single valve type covers both standard Spitzer air circuits and more demanding applications.

Specifications and Materials

Standard Version (Classic and Stainless)

Heavy-Duty Stainless Version (V4A)

Sizes and Types

Air ball valves are selected based on four parameters: DN size (mm), internal thread (inches), body length (mm), and working pressure (bar):

Working pressure values apply to the standard version (nickel-plated brass). The appropriate size is matched to the thread and connection pressure of the specific trailer.

Compatibility with Spitzer Silo Trailers (SF/SK)

PTFE-sealed air ball valves are matched to the diameter and thread of the air connection point within the Spitzer SF and SK pneumatic system. The standard version (nickel-plated brass, chrome ball, PTFE) covers the typical requirements of silo trailer pneumatic circuits in the -40°C to 120°C range. Where the application demands higher pressure or acid resistance, the heavy-duty V4A version is the appropriate choice.

The absence of a handle lock makes operation straightforward — a single quarter-turn is all that is needed. During installation, correct matching of internal thread size and body length to existing pipework is essential. For segmented or aluminium bulk goods valves (ZR type / Prokosch), please refer to the dedicated categories — this section covers air valves only.

Common Faults in Spitzer Silo Trailers

In service practice, the most frequent fault with a ball valve is loss of seal integrity caused by wear of the PTFE seats — the valve passes air even in the closed position. The second common issue is resistance or stiffness in the ball’s rotation, resulting from deposits, contamination, or corrosion of steel components due to insufficient maintenance.

In high-pressure or chemically aggressive environments, the brass version may not be adequate — in such cases, we recommend switching to the V4A stainless version (up to 63 bar, up to 180°C). During regular operation it is worth checking handle freedom of movement and seal integrity in the closed position at each scheduled inspection.

Selection and Service Considerations for Spitzer SF/SK Silo Trailers

In Spitzer SF and SK aluminium silo trailers, air ball valves are concentrated around the pneumatic distributor and at branch points leading to individual compartments — they determine which section of the tank the driver pressurises at any given point during discharge. The key consideration here is not maximum size but consistency: the SF/SK series uses the same connections repeatedly across many nodes, so it is cost-effective to keep one proven valve type in stock and replace it preventively rather than waiting for a seal failure mid-run.

A wear pattern we regularly observe during Spitzer SF/SK service is the gradual hardening of PTFE seats in valves closest to the compressor — these operate at the highest temperature and are the first to lose reliable ball contact. When overhauling the pneumatic circuit of a Spitzer silo trailer, diagnosis should therefore start with those valves, and if problems recur in that location, upgrading to the heavy-duty V4A version is worth considering. A second factor to bear in mind when fitting valves in SF/SK trailers is access to the handle: tight chassis packaging can restrict the quarter-turn movement, so during installation the valve length and orientation should be chosen to keep operation comfortable despite the absence of a handle lock.

It is also worth noting the role of condensate in the Spitzer SF/SK pneumatic circuit. Compressed air carrying moisture settles in the lowest-mounted valves, and regular system drainage noticeably extends the service life of the chrome ball and PTFE seat. In the SF/SK series, where there are relatively many valves, standardising on a single fitting type from a single source simplifies both inspection and spare parts management.

Availability and Delivery

Standard and stainless air ball valves are dispatched from the PHS Magnum warehouse in Chorula, near Opole. The heavy-duty V4A stainless steel version is available as a permanent direct-supply item.

• 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 size and specification selection to suit your installation: Spitzer service team, tel. +48 602 716 551. Full range of services: magnumchorula.pl/en/service/.

Related Categories

• Segmented Ball Valves — segmented air ball valves, ZR type (Spitzer)
• Non-Return Valves — inline and angled non-return valves
• Prokosch Bulk Goods Ball Valves — aluminium bulk goods ball valves, Prokosch type
• Spitzer Spare Parts Catalogue — full overview of all categories

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).