Technical 1-1/2" Winter Rubber Test Plug with Blow-Thru Stem – Open-Stem Valve for Pressure Testing and Winterizing

TECHNICAL's Winter Rubber Plug with Valve is a 1-1/2" open-stem test plug with a 1/8" pipe thread and 3/8" hose barb that lets you introduce air or water pressure and blow out lines for testing or winterizing.

This cast-rubber test plug is built for plumbing and irrigation tasks where creating a temporary, pressure-capable seal is required. The open or "blow-thru" stem provides a straight-through channel so you can attach pressure sources or hoses directly to the plug. That design makes it a compact, reusable tool for pressure testing, clearing blockages, and winterizing outdoor lines without modifying the pipework.

How does the open stem help with pressure testing?

The open stem provides a full passage through the plug so air or water can be routed into the enclosed pipe. That direct channel simplifies connection of gauges, pumps, or air hoses, reducing the need for extra fittings. It also lets you control pressure and observe system responses while the rubber body creates a tight seal around the pipe ID.

• Open center stem for direct hose or gauge attachment
• Compatible with air or water pressurization for leak detection
• Quick install to isolate sections during testing

What fittings are on the top and why do they matter?

This plug includes a 1/8" pipe thread paired with a 3/8" hose barb to maximize versatility. The pipe thread accepts common pressure fittings or adapters, while the barb securely holds flexible hoses for blowing out or introducing fluids. Together they reduce the number of adapters you need on site and speed up setup.

• 1/8" pipe thread for threaded gauges or adapters
• 3/8" hose barb for quick hose connections
• Works with standard shop pumps, compressors, and garden hoses (with suitable adapter)

Can this plug be used for winterizing and clearing blocked lines?

Yes — the blow-thru stem lets you push air or water through a section to remove debris or moisture before cold weather. By sealing the pipe and directing flow out the opposite end, you can evacuate water that would otherwise freeze and damage piping. The rubber body also tolerates repeated installations typical of seasonal maintenance.

• Blow-out capability helps remove trapped water before freezing
• Useful for clearing sediment and small blockages with pressurized flow
• Reusable design suitable for seasonal maintenance tasks

Who is this for? Plumbers, irrigation technicians, maintenance crews, and DIY homeowners who need a reliable, temporary sealing and pressurization solution will find this TECHNICAL plug useful. It’s ideal when you require a compact tool for isolating a 1-1/2" pipe segment while applying pressure, running diagnostics, or clearing/evacuating lines. If your work involves winterizing outdoor systems, pressure testing new installations, or troubleshooting leaks without cutting or permanently altering piping, this open-stem plug (Manufacturer Part #045) offers a practical, easy-to-deploy option.