Measures: 21" OD & 10" ID
Covers: 12" x 12" square hole
Weight: 6 lbs
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Seal-R® Adapter Rings by BrenLin
Installer-built adapter rings for watertight sealing, exact fit, and cleaner installs.
Seal-R® Adapter Rings are solid LDPE rings designed to seat on concrete tanks and create a watertight seal that helps prevent infiltration. Built for new installs and retrofits, they provide a dependable tank-to-riser connection with less rework.
Seal-R® Adapter Rings by BrenLin
Installer-built adapter rings for watertight sealing, exact fit, and cleaner installs.
Trusted for Cleaner Installs & Fewer Callbacks
Concrete tank openings vary, surfaces aren’t always perfect, and the riser connection is only as reliable as the interface underneath it. Seal-R® Adapter Rings create a solid seating surface at the tank, supporting a watertight connection and consistent riser fit from the start—reducing issues like shifting, leakage, and extra field adjustments.
Reliable tank-to-riser interface
Designed to seat on concrete tanks and create a dependable connection point for the riser system so installs start clean and stay secure.
Watertight seal design
Built to help prevent water infiltration at the tank interface, protecting the opening from groundwater entry and runoff.
Size coverage that reduces guesswork
Multiple sizes designed to cover common access openings, including square openings up to the listed dimensions.
Available Sizes & Full Specifications
Seal-R® Adapter Rings are available in 12"–36" sizes to match common septic tank access openings and riser applications. Each ring is designed as a stable tank interface, with OD/ID dimensions and opening coverage to support repeatable installs and a watertight seal at the concrete tank-to-riser connection. Built to be specified as part of the Seal-R® riser system, these standard sizes support both residential and light commercial septic configurations where fit and seal integrity matter.
15″ Seal-R® Adapter Ring
Measures: 21" OD & 13" ID
Covers: 13" x 13" square hole
Weight: 5.5 lbs
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Covers: 13" x 13" square hole
Weight: 5.5 lbs
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18″ Seal-R® Adapter Ring
Measures: 27" OD & 16" ID
Covers: 19.5" x 19.5" square hole
Weight: 9 lbs
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Covers: 19.5" x 19.5" square hole
Weight: 9 lbs
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24″ Seal-R® Adapter Ring
Measures: 33" OD & 22" ID
Covers: 24" x 24" square hole
Weight: 12 lbs
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Covers: 24" x 24" square hole
Weight: 12 lbs
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Need help determining the right size?
Contact us to select the correct adapter ring based on tank opening dimensions, riser configuration, and installation requirements.
Seal-R® Safety Covers: An Add-On Customers Ask For
Safety Covers add an extra layer of protection at the tank opening. If something makes it past the surface-mounted cover—or when the system is open during service—a Safety Cover provides a secondary barrier without changing the core Seal-R® setup. Designed to fit directly on top of the Seal-R® Adapter Ring, it’s an easy add-on when an extra layer of protection is needed.
Select the Safety Cover size to match the Adapter Ring size.
Testimonials
Backed by Customers
Testimonials
Backed by Customers
"I was in need of a septic chamber lid and base ring adapter to replace a concrete 36” manhole over my affluent septic chamber.... Through some conversation with Brady, it came to light that BrenLin sells the lids and base adapter rings to the septic company that I purchased my 24” lid from! Whoa small world. And I got an exact match! If you’re looking for quality septic products and great customer service to go with them, all from a real US based company, try BrenLin!"
Rich Rodriguez, BrenLin Customer - Google Review
Buying Options
Choose the purchasing path that fits your job and timeline.
FAQs
For Installers & Distributors
For Homeowners
Built to Perform. Spec’d for a Watertight Seal.
BrenLin designs and manufactures Seal-R® Adapter Rings to create a dependable tank interface for riser systems supporting watertight tank-to-riser connections, repeatable sizing, and fewer failure points in the field. Built for installers and distributors who need components that fit right and hold up over time.