Stub-Up Coupling With Knock-Out Seal for Slab Finishing
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Solution Overview
Problem
The presence of plumbing stub-ups extending above the concrete slab surface complicates the finishing of the slab, as they are prone to damage and require careful handling to avoid costly repairs, and also necessitate the use of insulating sleeves to account for thermal expansion differences.
Innovation Solution
A coupling system comprising a cylindrical coupler with a knock-out panel at one end, which is configured to receive a stub-up pipe and allows for pressure testing and debris prevention, while also enabling easy connection to the plumbing system when the slab is finished.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If stub-ups extend above the slab surface for connection, then plumbing connection is enabled, but the stub-ups are prone to damage and complicate slab finishing
Solution Approach 1:
The coupling device is divided into separate functional components: a protective housing that shields the stub-up connection point, and a separate access port for plumbing connection. This segmentation allows the stub-up to be protected while maintaining connection capability.
Solution Approach 2:
The coupling device acts as an intermediary between the stub-up and the plumbing system. It provides a protected interface where the stub-up connects internally while external connections are made through the housing, preventing direct exposure and damage to the stub-up.
2Ease of operation
If stub-ups extend above the slab surface, then plumbing connection is possible, but slab finishing becomes difficult and costly
Solution Approach 1:
The coupling device is installed on the stub-up before the slab finishing process. This preliminary installation allows the slab to be finished to a smooth surface without needing to accommodate protruding stub-ups, eliminating the need for costly post-finishing repairs.
Solution Approach 2:
The coupling housing serves as an intermediary structure that sits flush with or below the slab surface, allowing the slab to be finished normally while still providing access for plumbing connections through the housing's access ports.
3Adaptability or versatility
If insulating sleeves are placed around stub-ups, then thermal expansion differences are accommodated, but the complexity of the installation increases
Solution Approach 1:
The coupling device combines multiple functions into a single integrated component: it provides the connection interface, incorporates the insulating sleeve functionality within its housing structure, and provides protective shielding. This merging eliminates the need for separate insulating sleeves and reduces installation complexity.
Solution Approach 2:
The coupling housing serves multiple purposes simultaneously: it protects the stub-up connection, accommodates thermal expansion through its design, provides access ports for plumbing connections, and interfaces with the slab surface. This multi-functionality replaces the need for separate insulating sleeves and other components.
Data Source
AI summary
A coupling system for plumbing applications including stub-ups in a poured slab. The coupling system includes a coupler and a cap. The coupler provides a glue-hub that is couplable to a stub-up. An opposite end of the coupler is enclosed by a knock-out disc that seals the end of the stub-up for pressure testing. A second glue-hub is provided beneath the knock-out disc. The cap includes a cap plate enclosing a top end thereof and is height adjustable on the coupler. A thermal expansion gap between the slab and the stub-up is provided by a sleeve positionable around the cap. The cap plate and the knock-out disc are “knocked out” to enable connection with the plumbing system and are sized to resist falling into the stub-up. An air purging valve may be installed in the coupler for pressure testing prior to removing the knock-out discs in the cap and coupler.