LQ-SR
Standard Rotary Airlock Valve
General-purpose airlock for gravity discharge of free-flowing powders and granules.
LQ-BT · Product
Blow-through Rotary Valve
Air-swept design for feeding fine powders into positive pressure pneumatic conveying lines.
Product Overview
A blow-through valve introduces the conveying air directly into the rotor pocket, so material is swept out of the valve as it rotates past the air inlet instead of falling into an air stream below the valve. This avoids the pressure build-up and blow-back problems that occur when a standard valve is used to feed a pressurised line, and it is the usual choice for fine, dusty materials such as cement, fly ash and mineral filler.
Product Structure
Housing
Air inlet port machined into the housing side, with a replaceable air-swept wear insert at the discharge point.
Rotor
Closed rotor with reduced pocket volume and tight tip clearance, matched to the conveying air volume.
Shaft & bearings
Outboard bearings with air-purge seals to keep fine powder out of the bearing cavity under line pressure.
Sealing
Packing plus shaft air purge as standard; mechanical seal option for high pressure duty.
Drive
Geared motor with VFD for rate control against line pressure signal.
Typical Specifications
| Valve size | DN150 – DN400 typical; other sizes built to drawing |
|---|---|
| Rotor | Closed rotor, tight clearance |
| Rotor speed | 20 – 40 rpm typical, VFD recommended |
| Drive | Geared motor 0.75 – 3.0 kW with VFD |
| Housing material | Carbon steel / 304 / 316L |
| Rotor material | Carbon steel / 304 / 316L, wear-coated option |
| Operating temperature | Up to 200 °C standard build |
| Air connection | Integral blow-through port, flanged to customer line |
Values shown are typical for this product family. Final dimensions, materials and performance are confirmed on the approved drawing before production.
Design Features
- Air inlet port sized to the conveying air volume, not the material flow
- Closed rotor to limit air loss through the pocket
- Replaceable wear insert at the air-swept discharge zone
- Bearing isolation for continuous operation under line pressure
- Compatible with dilute-phase positive pressure systems
Material Options
- Carbon steel with ceramic wear insert — cement, fly ash, alumina
- 304 / 316L stainless steel — fine chemical powders
- Hard-chrome plated rotor — abrasive fine minerals
- Air-purge seal package — fine dust under pressure
Customisation
Every valve in this range can be built to your drawing: face-to-face length, flange pattern, rotor profile, material grade and drive arrangement. Send your drawing and we will quote against it.
Frequently Asked Questions
What air pressure can the valve work against?
The valve is a mechanical feeder, not a pressure vessel. Acceptable differential pressure depends on rotor clearance, seal arrangement and drive torque; we confirm it against your conveying pressure before quoting.
Do I need a blow-through valve or a standard valve with an air injector?
If your conveying line runs at positive pressure and the material is fine, a blow-through valve is normally the cleaner solution. For low pressure or short runs a standard valve with a separate air injector can work and costs less.
Can it handle vacuum conveying?
A blow-through valve is intended for positive pressure feeding. For vacuum systems we recommend a valve with air-purge seals and a closed rotor, sized to the permitted in-leakage.
Looking for a reliable rotary airlock supplier?
Send us your drawings or application requirements. Let us find the right solution for your equipment.