Chorula k. Opola 4 km from motorway A4 Mon-Fri 06:00-20:00
+48 602 716 551

Discharge Valves

Discharge valve service for Spitzer SF/SK silo trailers: butterfly valve replacement, reconditioning, calibration and EPDM/PTFE seal replacement. Aluminium and 316L SS. Chorula, ISO 9001:2015.

Silo trailer and specialist semi-trailer service facility

In Brief

PHS Magnum services discharge valves on Spitzer SF and SK series silo trailers: butterfly valve replacement, reconditioning (disc grinding, body polishing), EPDM/PTFE/FDA silicone/Viton seal replacement, and leak testing. Materials available: standard aluminium and 316L stainless steel for food-grade and chemical applications. Valves in sizes DN100–DN150 are held in stock, with full seal kits available for all sizes. A standard job typically takes two to four working hours; mobile on-site service is also available. Based in Chorula near Opole, ISO 9001:2015. Ask for a quote.

Spitzer Discharge Valves — Service and Replacement

Discharge valves are the most frequently repaired components on a silo trailer — they operate on every unloading cycle and are exposed to both mechanical and chemical wear. PHS Magnum specialises in the replacement and reconditioning of discharge valves on Spitzer SF and SK series silo trailers.

Valve Types Used on Spitzer Trailers

Butterfly Valve

The standard for Spitzer silo trailers. Actuation: pneumatic or manual. Configurations:

  • DN100 (4 inch) — smallest size, for precise metering
  • DN125 (5 inch) — most common for PE/PP granulates
  • DN150 (6 inch) — higher discharge rates, lighter bulk materials
  • DN200 (8 inch) — selected special-build models

Bottom Valves

Some Spitzer configurations use bottom valves instead of butterfly valves. Design: internal pressure-vessel valve with pneumatic actuation. More complex to service (requires internal vessel access).

Diverter Valves

Used in multi-compartment configurations to direct flow from individual compartments into a shared outlet pipe. Specialist components, replaced less frequently.

Butterfly Valve Replacement Procedure (PHS Magnum)

Step 1: Diagnostics

  • Visual inspection of seal condition (checking for leakage)
  • Measurement of disc seating surface wear
  • Assessment of the actuation mechanism (pneumatics or manual lever)

Step 2: Removal

  • Emptying and disconnecting the pneumatic circuit
  • Disconnecting flanged pipes on both sides of the valve
  • Unbolting the valve from its mounting

Step 3: Replacement or Reconditioning

  • Replacement: fitting a new valve (from stock or ordered in)
  • Reconditioning: disc seating surface grinding, seal replacement, body polishing

Step 4: Refitting

  • New flange gaskets on both sides
  • Torquing to Spitzer specification
  • Reconnecting the pneumatic circuit
  • Leak and function test

Step 5: Operational Test

  • 10–20 open/close cycles
  • Leak check under working pressure
  • Entry in the service log

Operation time: 2–4 working hours for a single standard DN100/DN125 valve.

Most Common Spitzer Valve Faults

Material Leaking Past the Valve

Cause: worn EPDM/PTFE seal (most common), worn disc seating surface, mechanical body damage.

Resolution: seal replacement (cheapest and fastest) → reconditioning (disc grinding) → full valve replacement (when the body is beyond use).

Valve Seized (Will Not Open or Close)

Cause: residual bulk material drying inside the valve chamber (cement and lime harden particularly fast), corrosion of the pivot pin, pneumatic actuator fault.

Resolution: disassembly, cleaning, pin lubrication, pneumatic system inspection.

Internal Corrosion

Cause: transport of alkaline materials (cement, lime) combined with inadequate post-cycle maintenance (flushing and drying).

Resolution: reconditioning (for light corrosion) or full valve replacement.

Mechanical Damage (Impact)

Cause: insufficient care during loading, impact from a foreign object.

Resolution: always full valve replacement (reconditioning is not appropriate — the mounting geometry may be compromised).

Butterfly Valve Selection — Sizes and Applications

SizeInchesTypical Application
DN1004"precise metering, lower flow rates
DN1255"standard for PE/PP granulates
DN1506"higher discharge rates, lighter bulk materials
DN2008"selected special-build models

Body material and seal selection depends on the cargo carried: aluminium with EPDM for granulates, cement, and lime; 316L stainless steel with FDA silicone for food products (flour, sugar, starch); PTFE or Viton for chemicals and high temperatures. All of these are held in stock — full listing in the Spitzer SF / SK spare parts section.

What PHS Magnum Offers

  • Spitzer valve stock — DN100/125/150 standard sizes, available off the shelf
  • Full seal kits in all materials (EPDM, FDA silicone, PTFE, Viton)
  • Valve reconditioning — when cost-effective, with a 6-month warranty
  • Documented replacement — service log entry, material certificates for new parts
  • Mobile service — on-site valve replacement at customer premises (200–300 km from Chorula)

Contact

For Spitzer discharge valve diagnostics and replacement — provide the trailer model and serial number, describe the symptom (leak, seizure, corrosion), and we will confirm the scope and availability.

Tel: +48 602 716 551 · biuro@magnumchorula.pl Mon–Fri 06:00–20:00 · Sat 07:00–15:00

Related: Spitzer Service — Periodic Inspections · Spitzer Trailer Repair · TDT Inspection Spitzer · Discharge Valve Service · AKO Pinch / Membrane Valves · Butterfly Valves — other types · Spitzer Seals · Spitzer Pneumatics — Faults and Maintenance

Frequently Asked Questions

A butterfly valve is a quarter-turn regulating valve with a rotating disc inside a flanged body. Opening and closing is achieved by rotating the disc 90°. On a Spitzer silo trailer it controls the flow of bulk material from the discharge pipe. Materials: aluminium (standard) or 316L stainless steel (food-grade and chemical applications).

Typically when the seal (EPDM/PTFE) no longer provides a reliable shut-off even after replacement, when the disc shows significant wear on its seating surface, when the valve body has internal corrosion (common after 8–12 years of cement or lime haulage), or following mechanical damage (impact during loading or unloading).

It depends on the extent of the damage. Reconditioning — seal replacement, disc surface grinding, and fresh seals fitted on both sides — typically takes one to two working days. It pays off for older valves whose body is still sound but whose disc is worn, or for valves where original spare parts are no longer available from the manufacturer. Full valve replacement makes more sense when the body is corroded, when food-grade hygiene is critical, or when the cost of reconditioning approaches that of a new valve.

Seal selection for Spitzer silo trailer butterfly valves depends on the material being transported: EPDM — standard for granulates, cement, lime, and industrial bulk solids; FDA silicone — food-grade (flour, sugar, starch, dairy); PTFE/Teflon — high temperatures (above 100 °C) or aggressive chemicals; Viton/FPM — chemicals and oils. PHS Magnum will advise on the correct specification for your application.

Yes. Spitzer valve stock: DN100 aluminium standard (5+ units available), DN125 aluminium (3+ units), DN150 aluminium (2+ units), DN100/125 stainless steel 316L (available to order within 24–48 h). Full seal kits (EPDM, silicone, PTFE, Viton) in all sizes are available off the shelf.

Replacing an external valve (fitted outside the pressure vessel) does not affect the TDT inspection validity. Any internal valve or intervention on the pressure vessel structure must be reported to TDT and may require an extraordinary inspection. PHS Magnum carries out both categories of repair in full compliance with the relevant procedures.

Diagnostics first. If only the seal is worn, replacing it is the quickest and least costly fix. If the disc seating surface is worn but the body is still sound, reconditioning — disc grinding plus new seals — is the right call. Full valve replacement is recommended when the body is corroded or mechanically damaged. The decision comes down to component condition and cost: on a heavily worn valve, reconditioning can approach the price of a new unit.

Usually yes. Alkaline materials such as cement and lime harden quickly inside the valve chamber and lock the disc. Our standard approach is to remove the valve, clean the chamber thoroughly, lubricate the pivot pin, and inspect the pneumatic actuator. If we find pin corrosion or seal damage in the process, those parts are replaced at the same time. Preventive maintenance is straightforward: flush and dry the valve after each cycle with binding materials.

Yes, as part of our mobile service — typically within 200–300 km of Chorula. On-site we handle standard valve replacement, seal changes, and basic diagnostics. More intensive reconditioning work (disc grinding, body polishing) is carried out in our workshop. After every replacement the intervention is recorded in the service log and material certificates for the new parts are provided.

Contact & Hours

ul. Kościelna 9, 47-316 Chorula

Mon-Fri 06:00-20:00

Sat 07:00–15:00

+48 602 716 551 Contact us
DEKRA ISO 9001:2015 Quality Management Certificate — PHS Magnum

ISO 9001:2015

4 km from motorway A4

180 km from German border

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Pogotowie Techniczne TIR & SILO +48 602 716 551