Oatey 238-703 Knockout Test Cap 3 Inch Plastic

Product Description

The OATEY 238-703 is a 3-inch plastic knockout test cap used to pressure-test and air-test drain, waste, and vent (DWV) piping systems. The cap seals the open end of a 3-inch pipe, allowing the system to hold pressure during inspection. A knockout center lets the installer pop out the plug once testing is complete, restoring flow without removing the fitting. Licensed plumbers use this cap during rough-in inspections to satisfy local plumbing code test requirements.

This test cap is sized for 3-inch plastic pipe and is suited for residential and light commercial DWV applications. It is commonly used during new construction and remodel rough-ins where the authority having jurisdiction requires a witnessed pressure or air test of the waste and vent system before walls are closed. The knockout design saves time by eliminating the need to cut out a temporary cap after the test passes.

Key Features

• 3-inch pipe size fits standard plastic DWV pipe and fittings
• Knockout center allows single-tool removal after test completion
• Plastic construction is lightweight and compatible with PVC and ABS drain systems
• Designed for pressure and air testing of DWV piping per plumbing code requirements

Compatibility

Designed as an OEM-style test cap for 3-inch plastic DWV piping systems. Compatible with standard 3-inch PVC and ABS drain, waste, and vent pipe configurations typical in residential and light commercial plumbing.

Installation Notes

Installation is performed by a licensed plumber during the rough-in phase before inspection. Ensure the pipe end is clean and free of burrs before seating the cap to achieve a proper seal. Follow local plumbing code requirements for test pressure and duration. Remove the knockout only after the test has been witnessed and approved by the inspector.