Fernco QC-104 Flexible Pipe Cap 4 Inch Reusable

Product Description

The FERNCO QC-104 is a flexible PVC pipe cap designed to seal 4-inch pipe ends, cleanouts, and open test pipes quickly and without special tools. Manufactured from flexible polyvinyl chloride, it conforms to pipe ends for a reliable seal in both permanent and temporary applications. At 0.49 pounds and compact dimensions, it is easy to carry on the job and install without delay. Plumbers and drain technicians reach for this cap during pressure testing, rough-in inspections, and ongoing service work where a cleanout or pipe end needs to be sealed off reliably.

The QC-104 is suited for residential and light commercial plumbing work above ground and underground. It fits cast iron, steel, copper, and plastic piping, making it a versatile single-SKU solution across mixed-material drain, waste, and vent systems. Its reusable design makes it practical for service vans where the same cap may be needed on multiple calls. Plumbers routinely use it during rough-in pressure tests to temporarily block pipe ends before final fixture connections are made.

Key Features

• Flexible PVC construction conforms to pipe ends on cast iron, steel, copper, and plastic pipe
• Rated for above-ground and underground installation
• Reusable design reduces job-site material cost
• Suitable for permanent or temporary capping applications
• Fast hand installation with no special tools required

Compatibility

Designed as an OEM-style replacement and service cap for 4-inch drain, waste, and vent pipe ends across cast iron, steel, copper, and plastic piping systems.

Installation Notes

Installation is performed by licensed plumbers or qualified service technicians working on DWV systems. Before capping any pipe end during testing, verify all upstream valves or cleanout access points are closed and that the system is depressurized. For underground applications, ensure the cap is seated fully and check for proper fit before backfilling. Follow local plumbing codes and IPC guidelines when conducting pressure or leak tests on drain and vent systems.