In commercial and institutional buildings, reliable exit hardware is essential for life‑safety, code compliance, and day‑to‑day usability. Facilities with high occupant loads need exit devices that support smooth egress, withstand constant use, and integrate cleanly with the overall door hardware package. The Von Duprin 33A/35A Series Concealed Vertical Rod (CVR) Exit Devices is engineered specifically for these high‑traffic, design‑sensitive environments, combining robust construction with a clean, low‑profile appearance.
This guide explains where the 33A/35A Series performs best, why specifiers select it for demanding openings, and which hardware and configuration decisions matter most for long‑term performance.
Understanding the Von Duprin 33A/35A Series
The Von Duprin 33A/35A Series is a family of concealed vertical rod exit devices designed for use on pairs of doors, particularly where maintaining a clean sightline is a priority. Unlike surface vertical rod devices, the rods and latching mechanisms are housed inside the door, protecting components and reducing visible hardware.
Key characteristics and benefits
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Concealed vertical rods: Vertical rods run inside the door stiles rather than on the face of the door, protecting hardware from impact and tampering while preserving the door’s appearance.
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High‑traffic performance: The 33A/35A Series is built for doors that cycle constantly during the day, such as main corridors, circulation routes, and exit paths.
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Fire‑rated and non‑fire‑rated options: Available models and configurations like Von Duprin 3347AEO-F-4-100-711 Fire Rated, or can be used on both fire‑rated and non‑rated pairs when coordinated with appropriate doors, frames, and hardware.
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Broad trim compatibility: Compatible with a range of outside trims, including lever, pull, and escutcheon trims, allowing you to match security needs, aesthetics, and ADA considerations.
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Smooth operation: Designed to provide consistent latch retraction and relatching, which is critical both for everyday use and emergency egress.
Because they combine concealed hardware with heavy‑duty construction, these devices are well-suited for projects that care about both appearance and performance.
The 33A/35A platform also supports a wide range of electrified options, including electric latch retraction (EL/QEL), request‑to‑exit (RX) switches, latchbolt monitoring (LX), and combination monitoring kits, allowing specifiers to integrate these devices into modern access control and monitoring systems without changing the basic exit device footprint.
The 33A/35A exit devices also support a wide range of electrified options, including electric latch retraction (EL/QEL), request‑to‑exit (RX) switches, latchbolt monitoring (LX), and combination monitoring kits, allowing specifiers to integrate these devices into modern access control and monitoring systems without changing the basic exit device footprint. For example, electric latch retraction can be added using EL or QEL conversion kits such as 050070 (EL, 3' application) and 040063 (QEL, quiet latch retraction kit), while request‑to‑exit and latchbolt monitoring can be provided with RX and LX switch kits such as Von Duprin 050251 (RX switch kit) and combination RX/LX monitoring kits like Von Duprin 050259, all of which are available in Von Duprin parts selections on Qualitydoor.com.
Why the Von Duprin 33A/35A Series Excels in High‑Traffic Facilities
Before drilling into individual applications, it helps to understand the performance attributes that make this series a go‑to choice on many hardware schedules.
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Life‑safety and code‑ready design
The 33A/35A Series is available in configurations that support compliance with applicable building and life‑safety codes when installed as part of a properly designed opening. On required egress doors, the push pad provides single‑motion egress and a familiar operation method that occupants intuitively understand in an emergency. When paired with the correct fire‑rated components, these devices help maintain code‑required latching on fire door assemblies while still providing immediate egress from the interior side.
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Durability under constant use
High‑traffic facilities subject exit devices to repeated operation, abuse, and occasional misuse. The internal mechanism, vertical rods, and latching components of the 33A/35A Series are designed to tolerate this level of usage without quickly going out of adjustment. Concealing the rods inside the door also reduces the likelihood of accidental damage from carts, gurneys, luggage, and equipment, which is especially useful in healthcare, transportation, and hospitality environments.
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Architectural and aesthetic integration
Because the rods and top/bottom latches are concealed within the door, only the push bar and minimal external hardware are visible. This allows architects to maintain clean lines on wood, laminate, and decorative metal doors, and helps blend required life‑safety hardware into high‑end interiors. For projects with glass or custom architectural doors, the lower visual impact of concealed hardware can be a decisive advantage.
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Fire‑rating and opening compatibility
When correctly specified with fire‑rated doors, frames, coordinators, and latches, the 33A/35A Series can be part of a labeled fire‑rated pair. This combination helps ensure that doors in fire partitions and exit enclosures remain latched under fire conditions, while still allowing one‑motion egress on the push side.
For architects, facility managers, and security planners, these attributes make the 33A/35A Series a compelling choice wherever high‑traffic use, clean design, and code compliance converge.
Top Commercial Applications for the Von Duprin 33A/35A Series
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Educational Campuses
K‑12 schools, colleges, and universities contain a mix of classrooms, laboratories, gymnasiums, and assembly spaces that all feed into corridors and exit doors. These openings experience surges of traffic during class changes, events, and emergencies.
Typical applications include:
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Pairs of doors in classroom corridors and common areas.
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Exit doors on gymnasiums, cafeterias, and auditoriums.
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Secondary exits at the ends of classroom wings or residence hall corridors.
Why the 33A/35A Series fits education:
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Reliable, intuitive egress for students and staff during drills and emergencies.
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Durability under constant opening and closing throughout the school day.
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A clean, less “institutional” look that supports modern educational design.
In educational environments, administrators often need doors that lock from the exterior for security, while still providing free egress from the inside. Pairing 33A/35A devices with compatible trims and key systems allows schools to achieve both goals.
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Healthcare and Hospital Facilities
Healthcare facilities have especially demanding requirements for door hardware. Safety, accessibility, infection control, and staff workflow all must be considered. Corridors, patient wings, and treatment areas often rely on pairs of doors to accommodate beds, equipment, and staff movement.
Common healthcare uses:
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Pairs in patient room wings and treatment corridors.
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Exits serving intensive care, diagnostic, and surgical support areas.
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Cross‑corridor doors that subdivide smoke compartments or departments.
Why the 33A/35A Series works in healthcare:
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Concealed hardware reduces protrusions that can interfere with cleaning and disinfection protocols.
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Internal vertical rods are less exposed to impact from carts, wheelchairs, and beds.
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Consistent operation supports staff training and emergency response plans.
Where behavioral health or ligature‑resistant solutions are needed, the 33A/35A devices can be coordinated with appropriate trims and accessories chosen specifically for that risk profile.
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Government and Municipal Buildings
Government buildings often have a mix of high‑security, public‑facing, and administrative areas. Exit devices must support both security objectives and public life‑safety requirements.
Representative applications include:
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Courtroom exits and circulation doors.
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Public lobby exits lead to exterior routes or stair towers.
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Corridors serving administrative offices, council chambers, and hearing rooms.
Benefits in government environments:
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Professional appearance that aligns with the formality of courts and civic spaces.
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Heavy‑duty construction that stands up to high public use and occasional abuse.
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Versatility in trimming and keying to support complex access control policies.
Because many government projects standardize hardware across multiple floors and buildings, using a common device family like the 33A/35A simplifies maintenance and replacement planning.
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High‑End Commercial Offices
Corporate headquarters, law firms, financial institutions, and design‑driven workplaces prioritize both image and functionality. In these environments, exit devices must blend into carefully curated interiors while still satisfying egress requirements.
Typical door locations:
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Elevator lobbies and interconnecting stair doors.
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Conference center and training suite exits.
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Main interior circulation paths and multi‑tenant corridors.
Why specifiers choose the 33A/35A Series for offices:
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Minimal visible hardware complements glass, veneer, and custom wood doors.
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Compatible trims allow levers and finishes to be coordinated across office entries, side doors, and exit paths.
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Robust internal components handle intensive use in busy corporate corridors.
Because aesthetics are often just as important as performance in these spaces, concealed vertical rod devices offer a good balance of low visual impact and high reliability.
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Retail, Hospitality, and Entertainment Venues
Retail centers, hotels, convention facilities, and entertainment venues combine high occupant loads with constant movement. Doors may be exposed to luggage carts, event equipment, and heavy foot traffic.
Common applications:
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Exit doors from ballrooms, banquet halls, and meeting rooms.
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Back‑of‑house corridors in hotels, stadiums, and theaters.
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Mall and retail service corridors and emergency exits.
Advantages in these settings:
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Concealed hardware reduces snag points in narrow corridors used by staff and vendors.
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Devices withstand frequent cycles during events, peak shopping times, and shift changes.
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Clean design helps preserve the guest experience in public‑facing areas.
When paired with appropriate signage and lighting, 33A/35A devices also contribute to clear wayfinding in complex hospitality and retail layouts.
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Transportation Hubs and Transit Facilities
Airports, train stations, bus terminals, and intermodal hubs see some of the highest pedestrian volumes in any facility type. Doors in these buildings may be in near‑constant use.
Typical applications:
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Exit doors from concourses, platforms, and waiting areas.
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Cross‑corridor doors that help compartmentalize smoke and manage crowd flow.
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Secondary exits that see heavy use during peak travel periods or events.
Why the 33A/35A Series is well‑suited:
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Robust construction tolerates heavy usage and harsh handling.
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Concealed rods are protected from carts, luggage, and equipment impact.
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When coordinated with fire‑rated doors and frames, devices help maintain required fire and smoke control in exit paths.
For mission‑critical facilities such as airports and transit hubs, reliability and ease of maintenance are particularly important; a standardized, durable device family simplifies both.
Specifying the Right Von Duprin 33A/35A Configuration
Choosing the correct 33A/35A exit device is about more than picking a model number. You need to align the device with the door, occupancy type, and code requirements for each opening.
Key specification considerations:
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Door type and thickness: Verify compatibility with the door construction (hollow metal, wood, or specialty) and thickness range.
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Fire rating: Confirm whether the opening is fire‑rated and ensure the selected device, latches, and related components are listed and labeled for that application.
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Trim style and function: Select exterior trim (lever, pull, escutcheon, or keyed function) based on security needs, ADA considerations, and the required locking function.
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Hardware coordination: Coordinate the exit device with door closers, hinges or pivots, coordinators (for pairs), strikes, and seals to ensure smooth operation and compliance.
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Code and project requirements: Review local amendments, project specifications, and owner standards regarding hardware type, finish, electrification, and access control integration.
For projects that involve access control or monitoring, 33A/35A devices can be coordinated with electric strikes, request‑to‑exit devices, and door position switches as needed.
Qualitydoor.com can support specifiers and facility teams with product selection, hardware set review, and compatibility questions to ensure that Von Duprin 33A/35A devices are correctly matched to each opening.
Maintenance and Lifecycle Planning for High‑Traffic Facilities
Even the best exit devices require periodic attention. A proactive maintenance program helps protect code compliance and avoid surprise failures.
Recommended practices include:
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Routine inspections: Periodically operate each device to confirm the push pad moves freely and the top and bottom latches fully engage and retract.
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Lubrication and adjustment: Follow manufacturer guidelines for lubrication intervals and adjust rods, latches, and strikes if hardware shows signs of drag, misalignment, or incomplete latching.
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Fire and egress inspections: For fire‑rated and egress doors, verify that devices function correctly during required life‑safety inspections and that no unauthorized field modifications have been made.
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Component replacement: Replace worn end caps, trims, or latches before they cause operational issues, especially in entrances and exits that are critical to operations.
In high‑traffic buildings such as hospitals, transit hubs, and large campuses, documenting maintenance activities and hardware configurations can significantly extend the service life of 33A/35A devices and reduce downtime.
Why Source Von Duprin 33A/35A Exit Devices from Qualitydoor.com
Selecting the right exit device is only one part of ensuring safe, code‑compliant openings. Reliable sourcing, correct configuration, and technical support are just as important.
Qualitydoor.com provides:
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Genuine Von Duprin 33A/35A Series concealed vertical rod devices for fire‑rated and non‑rated pairs.
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Guidance on matching devices, trims, and accessories to ADA, fire, and egress requirements for your project.
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Fast, accurate order fulfillment to keep construction and renovation schedules on track.
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Specification assistance for architects, contractors, and facility managers building standardized hardware sets across multiple locations.
For high‑traffic facilities that demand safe, clean‑looking, and durable egress solutions, pairing Von Duprin 33A/35A Series exit devices with knowledgeable support from Qualitydoor.com delivers a reliable, long‑term door hardware strategy.