Dorex 784DU Door Closer #4 Power Duranodic Doors w/Backcheck

Product Overview

The Dorex 784DU Door Closer (Size 4 Power) is a heavy-duty commercial door closer designed for high-traffic and exterior applications. This model includes backcheck, providing additional protection against door damage caused by forceful opening or wind pressure.

The DU (Duranodic) finish offers a dark bronze appearance commonly specified for aluminum storefront and architectural door systems.

Key Features

• Size 4 Spring Power – Suitable for wide and heavy commercial doors
• Integrated Backcheck – Cushions the door during opening to prevent wall and hardware damage
• Duranodic (DU) Finish – Dark bronze finish ideal for storefront systems
• Rack and Pinion Mechanism – Smooth, controlled closing performance
• Adjustable Sweep & Latch Speed – Independent speed control valves
• Surface Mounted Design – Compatible with wood, hollow metal, and aluminum doors
• Non-Handed Installation – Works on left or right-hand doors

What Is Backcheck?

Backcheck is a hydraulic feature that slows the door during the opening cycle, helping to:

• Reduce stress on hinges and frames
• Prevent damage from strong winds
• Protect adjacent walls and hardware
• Extend overall door system lifespan

Backcheck is especially important for exterior doors and high-traffic entrances.

Recommended Applications

• Exterior commercial entrance doors
• Aluminum storefront doors
• Schools and institutional facilities
• Industrial buildings
• High-traffic openings exposed to wind

Technical Specifications (Typical for Size 4 Closers with Backcheck)

• Door Width Range: Typically up to 42"–48" (depending on door weight and conditions)
• Mounting Type: Standard surface mount (regular arm)
• Material: Cast aluminum body
• Adjustments: Sweep speed, latch speed, and backcheck
• Arm Type: Standard arm included
• Finish: Duranodic (Dark Bronze)

When to Choose the 784DU

Choose this model when:

• The door is heavy or wide
• The opening is exposed to wind
• The door experiences frequent use
• You require added protection from forced opening

The Dorex 784DU delivers heavy-duty performance with added backcheck protection, making it ideal for demanding commercial environments.