Doebritz Interchangeable Screen Rotary Valve: Cast Iron / Stainless Steel – Minimal Air Leakage (ATEX Ready)

Rotary Airlock Efficiency Redefined

For over 15 years, Doebritz has engineered the Interchangeable Screen series to be the benchmark for reliable rotary feeding and airlock sealing in heavy industries. Designed for continuous heavy-duty operation, this valve combines a precision-machined, replaceable screen with a robust rotor to ensure minimal air leakage and maximum volumetric efficiency. Whether you are feeding pneumatic conveying lines or discharging dust collectors, the Doebritz Interchangeable Screen provides the uncompromising performance expected by global OEMs and plant operators.

Why Global Plant Sourcing Chooses Doebritz Interchangeable Screen

Unlike standard rotary valves, the Doebritz design philosophy focuses on reducing total cost of ownership (TCO) and maximizing production uptime. Our valves incorporate advanced engineering features derived from top-tier German manufacturing standards.

• Minimal Air Leakage: Ultra-tight radial and axial clearances (as low as 0.1mm) achieved through 5-axis CNC machining, drastically reducing blow-by in high differential pressure systems.
• ATEX Certified Explosion-Proof: Full compliance with ATEX Zone 20/21 for dust and gas environments, featuring flameproof housing construction.
• Interchangeable Screen Design: The patented screen housing allows for rapid replacement without removing the end covers, minimizing downtime and spare parts inventory.
• Heavy-Duty Metallurgy: Available in Cast Iron (GGG40) or Stainless Steel (304/316L) with optional Ni-Hard or Stellite-coated vanes for extreme abrasion resistance.
• Outboard Bearing Configuration: Isolates bearings from the material flow, preventing contamination and extending MTBF (Mean Time Between Failures).

Precision Engineering: Housing & Rotor Assembly

The heart of the Doebritz Interchangeable Screen lies in its interchangeable liner. Machined from wear-resistant steel or engineered polymer, this screen can be replaced in under 30 minutes. The rotor itself is dynamically balanced and features a proprietary vane geometry that reduces material degradation while maintaining a steady, pulseless discharge. Each unit undergoes a 100% helium leak test before shipping, guaranteeing a leakage rate of less than 0.005 m³/h at 0.5 bar differential pressure. The shaft seals are equipped with air purge lantern rings as standard, providing an additional barrier against dust ingress into the gearbox.

Technical Specifications

Standard configurations are ready for integration into any bulk solids processing line. Custom DIN/ANSI flanges and drive mounts are available.

Specification	Standard Range
Body Material	Cast Iron (GGG40) / Stainless Steel (304/316L)
Rotor Design	8-Vane Open Rotor (10/12 vane optional)
Inlet/Outlet Size	150mm to 600mm (6 to 24 inches)
Capacity (Max)	Up to 80 m³/h (varies by rotor speed)
Max Differential Pressure	0.5 bar (7.25 psi) standard, 1.0 bar option
Operating Temp (Max)	-20°C to +250°C (-4°F to 482°F)
Flange Standards	DIN 2576 / ANSI B16.5 (Custom JIS available)
Leakage Rate (0.5 bar)	< 0.005 m³/h (helium tested)
ATEX Certification	II 1/2 D c T4 (Zone 20/21)

Heavy-Duty Application Scenarios

Pneumatic & Dense Phase Conveying

For dilute or dense phase systems, the Interchangeable Screen’s low leakage ensures system pressure stability. It handles plastic pellets, cement, fly ash, and chemical powders with equal efficiency. The optional polished rotor finish prevents material build-up (ratholing).

Dust Collector & Cyclone Discharge

When mounted under a cyclone or baghouse, the Doebritz valve acts as a reliable airlock, preventing pressure loss while continuously discharging collected fines. The rugged cast housing withstands high-temperature materials up to 250°C (480°F) with optional cooling fins.

Silo & Hopper Metering

Use as a volumetric feeder for controlled discharge from storage silos. The interchangeable screen protects the main housing from abrasive damage, turning a costly housing replacement into a simple, low-cost liner change.

Frequently Asked Questions

What does ‘Interchangeable Screen’ mean for maintenance costs?

In standard valves, abrasive wear damages the fixed housing bore, requiring expensive replacement. With Doebritz, the screen is the wear part. Replacing the screen costs 70% less than a new housing, dramatically lowering your TCO over 5 years.

Is the Doebritz Interchangeable Screen suitable for ATEX Zone 20?

Yes. All Doebritz Interchangeable Screen valves can be certified for ATEX Zone 20 (constant dust cloud) and Zone 21. We provide full certification documentation, including flamepath verification and temperature class assessment (T4/T5).

What materials can be handled?

The standard unit handles free-flowing powders and granules. For abrasive materials (silica sand, alumina), we recommend the Ni-Hard screen and Stellite hard-faced rotor. For sticky/hygroscopic materials, a polished 316L rotor with PTFE end seals is available.

Can you customize flanges and drive options?

Absolutely. Doebritz offers direct OEM supply with custom drilling patterns (DIN, ANSI, JIS) and direct gearmotor or hydraulic drive mounts. Lead times for custom builds are 10-15 working days via our agile CNC production line.

How does Doebritz guarantee minimal air leakage?

Every valve is CNC machined to tolerances of +/- 0.02mm. We use a combination of labyrinth seals and air-purged stuffing boxes on the shaft. Our helium test protocol at 1 bar differential ensures leakage rates are consistently under industry standards.