The Vortex® Roller Gate™ is the best choice for handling dry material in gravity flow or low-pressure applications. This gate is available in a wide variety of configurations including rectangular sizes and customer specific hole patterns. It has live-loaded seals that extend the service life by compensating for wear. These seals provide an excellent material seal across the gate and to atmosphere. They can also be replaced while the valve is in-line. Similar slide gates have seals made of soft packing, rubber or felt, which rapidly erode away allowing product leakage.
Ideal application: Installations above or below gravity-fed hoppers/silos, mixers, and augers/screw conveyors. It is also an excellent choice for application as an air shut-off gate/damper valve in vacuum dust collection systems. Custom sizes are available to accommodate any combination of gate stroke or width.
Optional Special Service Inlet protects rollers and minimizes material contact with the seals
Cam-adjustable rollers for in-line maintenance
Replaceable bonnet seals for in-line maintenance
Live loaded, wear compensating hard polymer bonnet & side seals
Positive seal of materials/dust-tight seal across the blade and to atmosphere
Mechanically self-cleans its seals with each actuation
No pinch points or exposed moving point for safety
No internal cavities to prevent wedging, lodging & spoilage
Narrow profile for limited space applications
Gravity flow only. Contact us to discuss suitability for use in low pressure/vacuum applications.
Non-abrasive to moderately abrasive powders, pellets, granules and dusts. Modifications available for handling sticky and/or corrosive materials, and for wash-down.
6 – 30 in | 150 – 760 mm
Contact us for custom sizes
Available in square or rectangular sizes. Round transition options are available
3 – 4 in | 75 – 100 mm
30 – 200 lb | 15 – 90 kg
Standard flange or CEMA flange
Custom flanges are available
180°F | 80°C for standard gate, with modifications that allow up to 400°F | 205°C
6061-T6 aluminum, 304 or 316L stainless steel
Material Contact Options
304 or 316L stainless steel
Bonnet & Side Seal Options
Nylon, PET, 25% glass-filled PTFE, felt
Load Seal Construction
PET, 25% glass-filled PTFE, hardened steel, stainless steel & bronze
End Seal Options
UHMW-PE, polyurethane, PET, 25% glass-filled PTFE
Double-acting air cylinder, hand wheel/crank, chain wheel, electric actuator
Magnetic reed, proximity or mechanical limit switches, and/or clear bonnet covers for visual indication
Material Flow Controls
AVP, IVP, VPO, VPC - Learn more >
Dual cylinder actuators
Sealed body air purge
Return Pan & Special Service Inlet
ATEX Zone 20 (internal), ATEX Zone 21 (external), FDA
Material/ Metal contact is 316L stainless steel.
Hardened steel rollers replace standard nylon rollers.
Modifications are made allowing 250 F (121 C) continuous to 300 F (149 C) intermittent service.
Modifications are made allowing 400 F (204 C) continuous to 450 F (232 C) intermittent service.
Gate blade is electropolished. Polyethylene (PET or UHMW) pressure plate seals are used to replace nylon.
Bonnet is manufactured with solid, gasketed covers. (Allows the valve to accept air purge.)
*Additional modifications available based on application.
Vortex Roller Gate vs. Alternatives
• Many alternative roller-supported slide gates rely on soft rubber seals which are directly exposed to the material flow stream. These seals rapidly erode or tear away in service. Others rely on bonnet packing, which can relax and allow material packing in the bonnet area. These deficiencies promote leakage of materials and dusts past the gate and to atmosphere, in addition to actuation issues and several other maintenance concerns. The Roller Gate addresses these issues by incorporating "live loaded" hard polymer bonnet seals and side seals. Hard polymer provides greater wear resistance and longer service life than alternative sealing materials. The hard polymer seals are "live loaded" with compressed rubber backing to ensure even as the polymer experiences frictional wear from many actuations over time, the rubber load seals continuously force the polymer seals against the sliding blade. When equipped with a Special Service Inlet, the seals and rollers are also shielded from the material flow stream, to protect them from abrasion. This design maintains the gate's positive seal of materials/dust-tight seal with infrequent maintenance intervention.
• Many alternative slide gates allow metal-on-metal sliding, which creates galling. This causes a gate to seize and bind, and can create foreign metal fragment contamination. The Roller Gate's hard polymer seals eliminate metal-on-metal contact to resolve each of these concerns.
• Many alternative roller-supported slide gates have open cavities where materials can wedge and prevent positive material shut-off. Wedging can also create seal wear and material degradation, and cause a gate to seize and bind. Wedged materials also create risk for cross-contamination and spoilage. To prevent wedging and ensure positive gate closure, the Roller Gate's sliding blade is designed to mechanically clear materials away from the sealing surfaces with each actuation. With each closing stroke, the Roller Gate mechanically self-cleans its side seals. With each opening stroke, the gate's bonnet seals prevent the blade from carrying materials back into the bonnet area. Both of these considerations ensure migrant materials are forced back out of the seals and are discharged into the process line, rather than packing in the seals and causing actuation issues.
• If materials and dusts begin to migrate and collect in the gate's bonnet area, it indicates that the gate's bonnet seals have partially worn and the compression load is lessened, causing the seals to no longer be forced against the sliding blade as they should be. With this maintenance indication, the Roller Gate features access slots on each side of the gate that allow bonnet seal replacement while the gate remains in-line. Using simple tools, new bonnet seals are driven into one access port as the worn bonnet seals are simultaneously ejected on the other side ofthe gate, through the opposite access port.
• When the Roller Gate is closed, if materials and dusts begin to leak past the sliding blade, it indicates that the gate's side seals have partially worn and the compression load is lessened, causing the blade to no longer be forced against the side seals as it should be. With this maintenance indication, the Roller Gate's cam-adjustable rollers can be utilized to restore the gate's dust-tight seal. Using simple tools, the cam rollers can be adjusted to lift the sliding blade against the side seals and restore the compression load. This maintenance process can be performed while the gate remains in-line, and can be repeated several times before the side seals must be replaced.