Technical Winter Rubber Plug for 1-1/2" Pipe with Blow-Thru Stem — 1/8" Thread & 3/8" Hose Barb, Pressure Test/Winterize

TECHNICAL's Winter Rubber Plug (Part 045) is a 1-1/2" open-stem test plug with a blow-thru valve designed to let air or water pass through the stem for pressure testing, line clearing, and winterizing.

This rubber plug combines a resilient sealing cuff sized for 1-1/2" pipes with an open stem that accepts a 1/8" pipe thread and a 3/8" hose barb on top. The combination makes it an adaptable tool for tradespeople and homeowners who need to pressurize systems, blow out waterlines for winterization, or clear obstructed runs. Its compact design and blow-thru stem let you connect pressure gauges, air hoses, or water feeds without removing the plug, saving time and reducing mess.

How does the open stem design make testing easier?

The open stem passes through the plug's center, creating a controlled access point to the sealed pipe without breaking the seal. You can introduce pressurized air or water through the stem to check for leaks, verify valve integrity, or confirm repair effectiveness. The top fittings accept standard connectors so setup is straightforward.

• Central bore allows direct pressurization while the plug remains sealed
• 1/8" pipe thread on top fits common pressure gauge fittings
• 3/8" hose barb accepts flexible hose for blowing or filling

Can this plug be used to winterize lines and blow out water?

Yes—connect an air source to the 3/8" hose barb to purge water from lines before freezing weather. The plug seals the pipe while allowing a steady airflow through the stem, making it effective for removing residual water. Use regulated, low-pressure air and follow standard plumbing safety practices.

• Creates a sealed access point for blowing out pipes
• Compatible with common shop air fittings and hoses
• Reduces the need for multiple temporary adapters

What sizes and fittings are included for compatibility?

This item is specified for 1-1/2" pipe openings and features a 1/8" pipe thread plus a 3/8" hose barb on the stem. That makes it compatible with many pressure gauges, bleeder valves, and shop hoses used in plumbing and HVAC work. The rubber sealing body conforms to pipe interiors to help ensure a reliable seal across typical 1-1/2" systems.

• Designed to fit 1-1/2" pipe bores securely
• 1/8" pipe thread for gauges or valves
• 3/8" hose barb for flexible hose attachment

How should I use and maintain the plug to get reliable service?

Before use, inspect the rubber body for cuts or hardening and confirm the stem threads and barb are clean. Lubricate lightly with a compatible rubber-safe lubricant for easier insertion and removal if needed. After each job, rinse debris from the plug, dry, and store in a cool place away from direct sunlight.

• Check seal condition before each application
• Use low regulated pressure and proper fittings
• Clean and store dry to prolong rubber life

Who is this for: The TECHNICAL Winter Rubber Plug with Valve (Part 045) is aimed at plumbers, HVAC technicians, maintenance crews, and DIY homeowners who need a compact, reliable tool for pressure testing, line clearing, or winterizing 1-1/2" pipe systems. If you routinely attach pressure gauges, blow out water lines, or perform field diagnostics on plumbing runs, this open-stem blow-thru plug offers a convenient, time-saving solution.