Exterior Folding
Limited space in the apparatus bay can be concerning, but with Door Engineering's Four-Fold XT™ inside-out design it is no longer an issue. The Four-Fold XT™ operator is interior mounted while the door panels fold to the exterior. This eliminates the bay space that is needed with the regular Four-Fold design.
Features
The Four-Fold XT™ door system is still built with all the benefits of our standard Four-Fold door. The heavy- duty design and construction of our Four-Fold door enables it to function under high cycle and other severe conditions, which create chronic service and maintenance problems for the conventional door alternatives.
Speed
Four-Fold doors clear the opening at an average speed of 24 inches per second. Conventional overhead and coiling doors operate between 8 to 12 inches per second.
- 14’ x 14’ Four-Fold Door = Less than 7 seconds to open
- 14’ x 14’ Overhead Door = 14 to 21 seconds to open
The high-speed operation of the Four-Fold door minimizes heating and cooling losses and reduces waiting time, increasing productivity and energy efficiency.
Horizontal Movement
The Four-Fold door moves horizontally rather than vertically. As a result, the door is visible throughout the opening motion allowing the driver to know the precise second the doorway is clear to exit. This allows an apparatus to move quickly and safely. It is common with overhead sectional and coiling steel doors for delivery vehicles, pick-up trucks or even passenger cars to begin driving through the door opening after losing sight of the bottom of the door, only to hit the bottom panel as they move through the opening. A collision of this type will make it impossible to operate the door (especially with telescoping and coiling steel doors, which cannot tolerate any denting or deforming of the slats). In contrast, the Four-Fold door is able to operate with similar abuse.
Maintenance
Standard preventative maintenance (PM) on Four-Fold doors includes applying grease to hinges and operators. With general yearly PM, Four-Fold door operators and components are designed to perform over 1 million cycles. Conventional sectional and coiling doors require constant spring and cable maintenance and replacement to keep them in safe working condition. Failure to keep up with costly PM on sectional and coiling steel doors can result in door failure, which can cause both damage to equipment and injury to personnel.
Manual Operation
Manual operation is available with the Four-Fold door system. With the simple pull of a cord, manual operation is quick and easy. It requires no springs under tensions or time consuming chain hoists or heavy lifting.
Safety Features
Standard features include: hinge guards that limit access to the hinge gap at each jamb and alert personnel to keep the area clear, fail-safe bump edges that sense obstructions that the phone eye and interior presence sensors may miss, and exterior light curtain photo eyes that provide continuous protection from the floor to 72” in height to sense both objects and personnel in that area. Optional features include: a LZR-Widescan presence sensor that provides sensing of pedestrians with 3 independent sensing fields for opening and closing, and an audio/visual warning beacon that provides a horn, strobe, and verbal annunciator to provide warning prior to automatic closing and during the opening and closing motion.
Sallyport Security Door System
Four-Fold sallyport door systems are a must for high security applications. Heavy duty tube steel constructed panels are available solid sheeted, glazed with security glass or inset with security of louvers. Designed to resist forced entry, sallyport systems feature detention grade locking mechanisms, tamperproof fasteners, ballistic resistant armor sheeting options and high-speed operation to assure your facility is secure.