ATEX Zone 20/21 Compliant Valve: Doebritz PE Star Discharge Valve | Certified Explosion Safety with 0.1-0.2mm Clearance

Product Overview: Doebritz PE Star Discharge Valve for Explosive Dust Environments

Doebritz presents the PE Star Discharge Valve – a certified explosion-proof rotary airlock engineered for Zone 20/21 hazardous dust atmospheres. Designed as a quick-release rotary valve, this model integrates precision-machined rotors with radial clearances maintained at 0.1–0.2mm, ensuring minimal air leakage across differential pressures up to 1.0 bar. The housing is manufactured from SUS304 or SUS316L stainless steel, with optional tungsten carbide or ceramic coatings for abrasive bulk solids. Every Doebritz PE Star valve undergoes 100% CNC machining verification and pressure decay testing before dispatch, delivering OEM-grade reliability for global process lines.

Why Plant Engineers Choose Doebritz PE Star Discharge Valve

• ATEX Zone 20/21 Certified Compliance: Full certification for dust explosion-proof zones, including flameproof housing construction and anti-static rotor configurations.
• Precision Airlock Sealing: Rotor-to-housing clearance of 0.1–0.2mm reduces air leakage to ≤0.001m³/h·bar, stabilizing pneumatic conveying pressure profiles.
• Quick-Release Demountable Design: Tool-free disassembly supports CIP/WIP cleaning and manual wash-down, cutting maintenance downtime by up to 70%.
• Heavy-Duty Material Options: SUS304/SUS316L, carbon steel with nickel plating, or PTFE/PE/polymer coatings for corrosion and wear resistance.
• Global OEM Supply Capability: Doebritz provides custom flanges (DIN/ANSI/HG20592), variable frequency drives, and Ex-proof motors for turnkey integration.

Housing & Rotor Engineering: Built for Explosion Isolation

The Doebritz PE Star discharge valve features a thick-walled housing cast to 16 bar pressure rating, designed to contain internal deflagrations without propagating flames. The rotor is precision-machined from wear-resistant stainless steel, with 6, 8, or 12-vane configurations available to match product flow characteristics. Outboard bearings with labyrinth seals isolate the product zone from gearmotor components, while a purge port allows nitrogen or air injection to prevent dust ingress into bearing blocks. All wetted surfaces are polished to Ra ≤ 0.8μm for hygienic applications, with mirror finish (Ra ≤ 0.4μm) optional for pharmaceutical lines.

Technical Specifications

The PE Star series supports inlet sizes from DN50 to DN350, handling volumetric capacities from 0.5 to 80 m³/h depending on rotor speed (VFD-controlled from 5–50 rpm). Maximum operating temperature ranges from -15°C to 120°C for standard seals, with water-cooled jacket options for higher thermal loads. The valve operates under positive pressure up to 1.0 bar or vacuum down to -0.8 bar, making it suitable for both pressure and suction pneumatic conveying systems. All Doebritz valves are hydrostatically tested to 1.5× rated pressure and helium leak-checked for airlock integrity.

Specification	Detail
Body Material	SUS304 / SUS316L stainless steel / Carbon steel with Ni plating
Rotor Design	6, 8 or 12-vane open rotor, precision machined clearance 0.1–0.2mm
Explosion Protection	ATEX Zone 20/21 certified, flameproof housing 16 bar rating
Pressure Range	-0.8 bar to +1.0 bar (low-pressure pneumatic / gravity / metering)
Temperature Range	-15°C to +120°C (standard); water-cooled jacket optional
Inlet Sizes	DN50, DN100, DN150, DN200, DN300, DN350 (HG20592 / DIN / ANSI)
Surface Finish	Ra ≤ 0.8μm standard, Ra ≤ 0.4μm mirror finish optional
Cleaning	Quick-release manual cleaning / CIP / WIP + manual inspection
Certifications	CE, TÜV, ATEX, Statement certification

Heavy-Duty Application Scenarios

Explosive Dust Pneumatic Conveying (Zone 20/21)

In lithium-ion battery material production (NMC, LCO, graphite anodes) or pharmaceutical API milling lines, the Doebritz PE Star valve isolates downstream equipment from upstream explosion risks. The certified flameproof housing and precision clearance prevent flame propagation, meeting ATEX directive 2014/34/EU.

Sanitary Food & Pharma Discharging

With 316L mirror-polished finish and quick-release clamps, the PE Star serves as a sanitary star discharge valve for dairy powder, coffee granules, vitamin blends, and probiotic cultures. CIP-ready design allows automated cleaning without disassembly, supported by Doebritz’s material certificates (3.1 EN 10204).

Abrasive Bulk Solids Handling

For cement, fly ash, carbon black, or silica fume, the internal surfaces can be coated with tungsten carbide (HVOF) or ceramic, extending rotor life by 300–500% compared to standard stainless steel. Doebritz offers wear-test reports for specific materials upon request.

Frequently Asked Questions

What is the standard lead time for Doebritz PE Star discharge valves?

Standard sizes (DN100–DN200) with stainless steel construction ship within 4–6 weeks. Custom coatings or ATEX-certified motors may add 2–3 weeks. Doebritz maintains regional stocking programs for high-volume OEM partners.

Can the PE Star valve handle sticky or cohesive powders?

Yes. Doebritz offers polished rotors, PTFE coating, and purged shaft seals to prevent material build-up. For hygroscopic products, the valve can be supplied with heated jackets to avoid condensation.

How is the 0.1–0.2mm clearance maintained over time?

The rotor and housing are CNC-machined from stress-relieved castings, and Doebritz uses adjustable end-cover shims to restore clearance after wear. Periodic inspection every 8,000 hours is recommended for abrasive services.

Does Doebritz provide ATEX documentation for global compliance?

Every valve includes a Declaration of Conformity for ATEX 2014/34/EU, as well as CE marking. Additional certifications (TÜV, TR CU, KCs) can be arranged for project-specific requirements.

What spares are recommended for stock?

Doebritz recommends keeping one set of rotor end-seals, shaft lip seals, and gaskets. For critical lines, a complete exchange rotor assembly minimizes downtime during maintenance.