Dorex 785DU Door Closer #5 Power Duranodic Doors w/Backcheck
785DUThe DOREX 700 Series fixed power door closer is recommended by door hardware specialists for use on a wide variety of residential and commercial applications with moderate traffic.
Product Overview
The Dorex 785DU Door Closer (Size 5 Power) is an extra heavy-duty commercial door closer designed for wide, heavy, and high-traffic doors. Engineered for demanding exterior and institutional applications, this model includes integrated backcheck to protect the door and frame from damage caused by forceful opening or wind pressure.
The DU (Duranodic) finish provides a dark bronze appearance commonly specified for aluminum storefront and architectural entrance systems.
Key Features
- Size 5 Spring Power – Maximum closing force for wide and heavy commercial doors
- Integrated Backcheck – Cushions the door during opening to prevent structural damage
- Duranodic (DU) Finish – Dark bronze finish ideal for storefront applications
- Heavy-Duty Rack and Pinion Mechanism – Smooth and controlled operation
- Adjustable Sweep & Latch Speed – Independent valve adjustments
- Surface Mounted Design – Compatible with wood, hollow metal, and aluminum doors
- Non-Handed Installation – Suitable for left- or right-hand doors
What Size 5 Power Is Used For
Size 5 closers are typically specified for:
- Extra-wide exterior doors
- Industrial or institutional facilities
- High-wind exposure environments
- Very high traffic openings
- Doors requiring maximum consistent latching force
Technical Specifications (Typical for Size 5 Closers with Backcheck)
- Door Width Range: Typically up to 48" and larger (depending on door weight and exposure)
- 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)
Benefits of Backcheck on Size 5 Closers
Backcheck is critical in heavy-duty applications because it:
- Reduces hinge and frame stress
- Prevents wall and hardware damage
- Minimizes door slamming in windy conditions
- Extends the lifespan of the entire door system
When to Choose the 785DU
Select the 785DU when:
- The door is heavy, wide, or oversized
- The opening is exposed to strong wind
- Traffic is very high
- Maximum closing control and durability are required
The Dorex 785DU is built for demanding commercial environments where reliability, strength, and protection are essential.
- For moderate traffic applications
- cULus listed
- 5 Year limited warranty
- Fixed power size 1, 2, 3, 4, or 5
- Non-handed
- Cast aluminum alloy body
- Hydraulic rack & pinion mechanism
- Non-gumming, non-freezing hydraulic fluid
- 180° maximum opening
- Adjustable sweep and latching speeds
- Tri-pack for regular, top jamb or parallel arm installations
- Adjustable cushioning backcheck models available
- Drop plates available
Product Page
Instructions
751 – Installation Instructions
752 – Installation Instructions
753 – Installation Instructions
754/755, 784/785 – Installation Instructions
Templates
751 – Regular Arm / Top Jamb
751 – Parallel Arm
752 – Regular Arm / Top Jamb
752 – Parallel Arm
753 – Regular Arm / Top Jamb
753 – Parallel Arm
754/755, 784/785 – Regular Arm / Top Jamb
754/755, 784/785 – Parallel Arm
Disclaimer
- We recommend that physical hardware be ordered and verified before starting any preparation, manufacturing or installation work.
- All product installations must be done by qualified personnel using the proper mounting hardware for the appropriate surface or material.
- We recommend that installers and manufacturers use the instructions inside the packaging provided by the manufacturer, as the manufacturer reserves the right to make technical changes, modify product or information without prior notice.
- Do not exceed the maximum weight or dimensions recommended by the manufacturer.
- All technical documents, drawings and instructions are provided as-is. Customers (primary or secondary) cannot derive any claim based on the use of these documents. No responsibility is or will be assumed.