Heavy-Duty Rotary Valve, Doebritz Airlock Feeder, Cast Iron / ATEX Certified / Minimal Air Leakage

Product Summary

Doebritz Heavy-Duty Rotary Valve series is engineered for continuous operation under extreme conditions. Delivering volumetric discharge capacities from 0.5 to 120 m³/h, these airlock feeders handle powders, granules, pellets, and flaky materials with ATEX certified explosion-proof safety for Zones 21 and 22. Maximum differential pressure up to 3.5 bar guarantees zero process interruption in dense-phase pneumatic conveying systems.

Why Source Doebritz Heavy-Duty Rotary Valves

Industrial procurement demands more than a part — it demands a long-term sealing partner. Doebritz integrates German-engineered tolerances with cost-effective CNC mass production.

• Ultra-Low Air Leakage: Leakage rate ≤0.5 Nm³/h at 1 bar differential pressure, validated via helium leak testing for every unit.
• Extended Service Life: Hardfaced rotor tips and stator liners (HRC 58-62) slash abrasive wear by 300% compared to standard cast iron.
• Global Compliance Ready: Standard ATEX II 2D Ex h IIIC T130°C Db, FDA-compliant seals for food contact, and SIL 2 capability.
• Fast Non-Standard Customization: From oblong flanges to Hastelloy bodies, typical lead time for engineered-to-order valves is 15 working days.

Housing & Rotor Engineering

The Doebritz heavy-duty rotary valve features a one-piece cast housing (EN-GJL-250 or CF8M stainless steel) with integrated end covers to eliminate leak paths. The drop-through design minimizes material hang-up, while outboard bearings mounted on a machined pedestal isolate the bearing cavity from product flow — critical for abrasive or hygroscopic materials. Rotor options include open-end, closed-end, or adjustable-tip vanes. Each rotor is dynamically balanced (ISO 1940 G6.3) for vibration-free operation up to 60 RPM.

Technical Specifications

All Doebritz valves are 100% tested before shipment. Parameters below represent the standard heavy-duty series. Pressure ratings, temperature ranges, and construction materials are upgradable per your process datasheet.

Specification	Detail
Body Material	Cast Iron EN-GJL-250 / Stainless Steel 304 / 316L
Rotor Design	8-Vane closed end, hardfaced tips (HRC 58+)
Inlet/Outlet Size	DN150 to DN500 (6 inch to 20 inch)
Capacity (Reference)	0.5 – 120 m³/h
Max Differential Pressure	3.5 bar
Operating Temperature	-20°C to +250°C (standard), up to +400°C (optional)
Leakage Rate	≤0.5 Nm³/h @ 1 bar
ATEX Certification	II 2D Ex h IIIC T130°C Db (standard)
Bearing Type	Outboard, sealed spherical roller bearings

Heavy-Duty Application Scenarios

Pneumatic Conveying Systems

As an airlock for dilute- or dense-phase transfer, the Doebritz rotary valve maintains system pressure while metering material into conveying lines. Typical applications include cement, fly ash, plastic pellets, and carbon black.

Silo Discharging & Dosing

Bottom-of-silo installation under silos, bins, or hoppers prevents bridging and provides accurate volumetric dosing for compounding lines or batch weighing systems.

Dust Filter Collectors

Mounted on dust collector hoppers, the valve seals against negative pressure while continuously discharging collected dust — ideal for mining, cement mills, and chemical plants requiring ATEX-certified operation.

Frequently Asked Questions

Q1: What is your standard lead time for a Doebritz heavy-duty rotary valve?

Standard sizes (DN150 to DN400) with cast iron housing are ready for shipment within 10 working days. Non-standard flanges, stainless steel bodies, or special coatings require 15-20 working days. Airfreight expedited shipping is available on request.

Q2: Can you supply custom inlet/outlet flanges (e.g., ASME, JIS, or non-standard bolt patterns)?

Yes — Doebritz specializes in OEM adaptations. We accept customer drawings and can machine any flange standard (ANSI, DIN, JIS, or custom PCD) without additional engineering fees for quantities above 10 units. For prototypes, a small tooling charge applies.

Q3: Is the ATEX certificate included as standard, and what zones are covered?

All Doebritz heavy-duty rotary valves include factory ATEX II 2D Ex h IIIC T130°C Db certification as standard for dust atmospheres. For gas explosion protection (II 2G Ex h IIB T4 Gb) or higher temperature classes (T150°C/T200°C), please specify during ordering. Third-party notified body certification (e.g., SGS, TÜV) is available at additional cost.

Q4: What high-temperature configurations are possible?

Standard PTFE lip seals operate up to 200°C. For applications up to 400°C, we offer a purged rotor end disc with graphite packing and air cooling fins. Above 400°C, a jacketed housing (steam or thermal oil heated) maintains seal integrity.

Q5: Do you provide repair kits or after-sales technical support for global customers?

Absolutely. Every Doebritz valve includes an online spare parts list with exploded view drawings. Wear parts kits (rotor tips, seals, bearing assemblies) are stocked in US, EU, and Asia hubs. Our engineers offer remote commissioning or on-site troubleshooting via our global service partner network.