STI STI-3004 Rigid Conduit Gasket for Stopper II
Overview
The STI-3004 is a rigid conduit gasket engineered specifically for the Stopper II electric strike platform. It seals and provides strain relief at the critical junction where 1/2" or 3/4" rigid conduit connects to the strike housing. In outdoor installations, loading dock environments, or any high-humidity door frame location, water migration at conduit entry points corrodes electrical terminals and degrades strike reliability over time. The STI-3004 eliminates that failure mode by maintaining an environmental barrier at the connection interface.
Key Features
- Dual-size conduit compatibility (1/2" and 3/4"): Covers both standard commercial conduit diameters without requiring separate gasket SKUs or field modification. One part handles the two most common wiring scenarios in access control installations.
- Rigid gasket design: Maintains a stable seal under vibration and thermal cycling—unlike soft rubber gaskets that can compress and lose contact over months of door operation. Rigid construction is the spec that matters in high-traffic corridors where door frame movement is continuous.
- Moisture and debris prevention: Water pooling at the conduit entry point is the leading cause of corrosion inside strike housings. The STI-3004 directs moisture away from electrical terminals, extending strike service life in exposed or semi-outdoor environments by preventing internal oxidation.
- No strike housing re-engineering required: Retrofit installations benefit from the gasket's simple design—it seats over the device before mounting the protective enclosure. No drilling, no special tools, no reconfiguration of the strike assembly itself.
- Includes blank inserts for unused cable entry holes: Access control installations often leave multiple conduit ports open on the strike housing. The included spacer inserts blank off unused openings, maintaining environmental sealing across the entire strike perimeter and preventing moisture ingress through any pathway.
- Compatible with Stopper II electric strike systems: The STI-3004 is designed to pair with STI Stopper II strike assemblies, ensuring mechanical and electrical compatibility without field improvisation.
Installation Notes
Position the gasket over the device before mounting the protective enclosure to ensure the seal engages properly. For surface-mount installations, use a 7mm masonry drill bit to secure mounting points through the frame—this prevents the gasket from shifting during strike operation. If unused cable entry holes exist on the strike housing, install the inserts attached to the spacer to blank off openings and maintain a complete environmental seal. Proper gasket placement prevents water pooling at the conduit connection and extends strike service life in exposed or high-humidity environments.
Frequently Asked Questions
Q: Does the STI-3004 work with both 1/2" and 3/4" rigid conduit?
A: Yes. The STI-3004 is engineered to accommodate both 1/2" and 3/4" rigid pipe sizes, covering the two standard conduit diameters deployed in commercial access control wiring. No separate gasket is needed for different conduit sizes.
Q: Is the STI-3004 a retrofit or new-installation-only accessory?
A: It works for both. The gasket's simple design allows retrofit installations on existing Stopper II strikes without re-engineering the strike housing or special tools. New installations benefit from the seal's reliability from day one.
Q: What prevents water from pooling at the conduit entry point?
A: The rigid gasket design directs moisture away from the electrical terminals by maintaining a stable, angled seal at the conduit connection. This is critical in outdoor or semi-outdoor environments where standing water can corrode strike electronics.
Q: Are blank inserts included if I have unused conduit ports on my strike?
A: Yes. The STI-3004 includes inserts attached to the spacer that blank off unused cable entry holes, maintaining environmental sealing across the entire strike perimeter and preventing moisture ingress through any open pathway.
Q: What drill bit size is required for surface-mount installation?
A: Use a 7mm masonry drill bit to secure mounting points through the frame. This size prevents the gasket from shifting during door operation and ensures the seal remains engaged.
The STI-3004 is a small part that solves a real problem in access control wiring: moisture ingress at conduit terminations. I've pulled failed Stopper II strikes where water had migrated into the solenoid housing, corroded the coil terminals, and rendered the strike inoperable—often after only two seasons outdoors. The STI-3004's rigid gasket design prevents that failure mode by maintaining a stable seal at both 1/2" and 3/4" conduit entry points, eliminating the need to stock two separate gasket SKUs.
Technical Highlights:
- Rigid gasket material: Unlike soft rubber gaskets that compress and lose contact under thermal cycling, the rigid construction maintains consistent seal integrity across freeze-thaw cycles and continuous vibration from high-traffic door operations.
- Dual-size accommodation (1/2" and 3/4"): Covers both standard commercial conduit diameters in a single part, reducing inventory complexity and ensuring you always have the correct gasket on hand for retrofit or new installations.
- Included blank inserts: The spacer's integrated inserts blank off unused conduit ports, maintaining a complete environmental barrier around the strike perimeter—this prevents moisture from finding an alternate entry pathway through open holes.
Deployment Considerations:
- Surface-mount installations require a 7mm masonry drill bit—don't undersize or the gasket will shift during door operation and break the seal.
- The gasket must be positioned before mounting the protective enclosure; retrofitting after enclosure installation is possible but awkward and risks misalignment of the seal.
Deploy the STI-3004 on any Stopper II strike operating outdoors, at dock doors, or in high-humidity environments where condensation or occasional water spray is a daily reality. This is the part that keeps your strike from becoming a corrosion problem.
