Gestra RV Check Valves

Introduction

Feldbinder silo trailers — both the horizontal, non-tipping EUT line and the hydraulically tipped pressure silo KIP (Kippsilo) — discharge pneumatically, under working pressure supplied by compressed air. Every such system must be protected against backflow into the supply circuit. This function is performed by the wafer disc check valve type RV (equivalent to the Gestra RK41), fitted between pipe flanges.

What sets Feldbinder apart is the density of its pressure pipework: check valves appear in the aeration line, in branch lines leading to the individual discharge outlets (EUT), and in the tipping-assist circuit (KIP). The greater the number of connection points, the more critical a sound, leak-free check valve becomes — a single leak can bleed off discharge pressure along the entire pneumatic run and noticeably extend silo-emptying time. For this reason, PHS Magnum treats the disc check valve as a pressure-rated component, not merely an auxiliary fitting.

PHS Magnum in Chorula near Opole holds a stock of RV-type check valves covering the full range of bore sizes used in Feldbinder silo trailers, with material certificates supplied with every delivery. The full parts catalogue is at /en/spare-parts/, and service information is at magnumchorula.pl/en/service/.

Specification and Materials

The RV-type disc check valve (Gestra RK41) is designed for wafer installation — it sits between two pipe flanges without a separate bolted body. The result is a compact, lightweight assembly that integrates cleanly into the dense pressure pipework of a silo trailer.

Stainless steel on the disc and spring provides corrosion resistance in the compressed-air environment, where condensate is a constant presence. The NBR seal ensures a metal-to-metal seal when the disc seats against the valve ring.

The operating principle is simple and reliable: forward flow lifts the disc, opening the bore; when inlet pressure drops or the medium attempts to reverse, the stainless spring pushes the disc back onto its seat and closes the flow path. The absence of electrical or actuating components means the valve operates automatically without any power supply — an important property in a silo trailer where all discharge pneumatics run on compressed air from the vehicle or the unloading station. The compact wafer construction shortens the installation length and reduces the weight of the assembly compared with full-body bolted valves.

Sizes and Types

RV-type check valves are available in four nominal bore sizes, covering the typical cross-sections of the Feldbinder pressure system:

Construction: metal-to-metal seating, brass body, stainless steel disc and spring, NBR seal. Bore selection is determined by the line cross-section where the valve is to operate.

In practice, DN50 and DN65 are used in smaller branch lines and auxiliary circuits, while DN80 and DN100 are fitted in the main aeration runs and higher-flow sections. Because the installation is wafer-pattern, interchangeability for a given DN depends on the flange standard of the connection in the trailer’s pipework. When ordering, please state the DN diameter and the direction of flow so that the valve can be fitted in accordance with the flow-direction arrow marked on the body.

Compatibility with Feldbinder Silo Trailers (EUT/KIP)

On the EUT line (horizontal non-tipping tank, pneumatic discharge via bottom outlets), RV check valves are fitted in the tank aeration line and in the branch lines leading to the individual discharge outlets. Multi-compartment EUT trailers have more branch lines, and therefore more points at which a properly sealed check valve determines whether discharge pressure is maintained evenly across every compartment.

On the KIP (Kippsilo) line — a silo tipped hydraulically to 45–50° where pneumatics assist discharge of poorly-flowing materials — check valves appear in the same pressure circuits as on the EUT. Valve selection depends on DN diameter and system pressure, not on trailer type, so the same range of sizes serves both designs. Wafer installation simplifies replacement: the valve is removed by uncoupling the flange, with no need to disturb the rest of the pipework.

Common Faults on Feldbinder Silo Trailers

In service practice, the disc check valves on Feldbinder silo trailers most commonly fail as follows:

• Backflow and loss of discharge pressure — most often a weakened or broken stainless spring, or a disc that no longer seats properly; the symptom is an extended silo-emptying time.
• NBR seal leakage — a hardened or cracked seal that no longer recovers its sealing function; the seal is a wear item and the complete valve is replaced.
• Seat contamination — fine particles of bulk material or condensate preventing the disc from fully seating; the valve opens but does not close reliably.
• Corrosion in the condensate environment — on Feldbinder trailers where part of the system is used with food-grade media, seals compatible with the specific medium should be selected (in demanding applications, Viton elastomers or 316L stainless elements are used where the assembly design permits). The stainless disc and spring limit corrosion within the mechanism itself.

In each of these cases, diagnosis begins with a leak-tightness check and confirmation that the disc seats correctly; if the disc or spring is damaged, the complete valve is replaced, as reconditioning a disc check valve of this class is not cost-effective.

Preventive maintenance is straightforward and inexpensive: drain condensate from the compressed-air system regularly, inspect check valves for tightness during scheduled services, and replace seals that have lost their elasticity. For Feldbinder fleets operating intensively on DACH routes, we recommend including a pressure-fittings check in the service schedule alongside the other pneumatic inspection points — identifying backflow at an early stage avoids extended unloading delays and complaints from bulk material receivers.

Availability and Delivery

• In stock at Chorula near Opole: RV check valves in DN50, DN65, DN80, DN100 — standard sizes available off the shelf.
• 24–48 h: most standard bore sizes.
• Direct delivery: non-standard sizes and special configurations on order.
• Shipping: courier (PL), GLS/DHL (DACH), EU VAT invoice.

Every delivery includes a material certificate. Technical advice on bore selection and installation point is available as part of PHS Magnum service.

Related Categories

• Check Valves — Other Types
• Safety Valves
• Pneumatic Hoses
• Hose Clamps
• Full catalogue: /en/spare-parts/

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, internal ISO 9001:2015 auditor (DEKRA).