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Secure and Tighten the Union — Install and Tighten the Coupling

Beginner3 hours

Part of project

How to Repair a Leaking Copper Pipe with a Compression Coupling · Step 6 of 7

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In this video

With the components in place, take the main body of the union adapter and push it firmly over the gasket and the end of the lead pipe until it is fully seated. Once the body is in place, slide the compression nut forward and begin threading it onto the main body by hand. Turn the nut clockwise until it is hand-tight. This action compresses the ring and gasket, creating the watertight seal.

Goal: Create a watertight seal

Used in this video

  • Safety Gloves (brand: Deltaplus)Protecting hands while tightening the fitting.
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FAQs

How difficult is this repair for a beginner, and what if it takes longer than 3 hours?

This repair is rated beginner because it avoids complex techniques like soldering. While the estimated time is 3 hours, allow extra time for locating the leak, gathering tools, and ensuring the pipe system is fully drained. Rushing can lead to mistakes, so prioritize careful, precise work over speed.

Do I really need all the specific tools listed, or can I use substitutes for this project?

While tools like a dedicated tubing cutter and reamer are highly recommended for achieving clean, burr-free pipe ends crucial for a leak-proof seal, some items like permanent markers or measuring tape can be substituted with similar household tools. An adjustable wrench is essential, so ensure you have one that fits the coupling nuts securely.

What's the most common mistake beginners make with compression fittings, and how can I avoid a new leak?

The most common mistake is not properly preparing the pipe ends (cutting straight, deburring, and cleaning) or improperly tightening the compression nuts. Ensure pipe ends are perfectly smooth and burr-free, and tighten the nuts until snug, then give an additional 1/2 to 3/4 turn. Avoid over-tightening, which can deform the ferrule or strip threads, or under-tightening, which causes leaks.

What are the most important safety precautions I should take when repairing a leaking copper pipe?

Always shut off the main water supply and drain the pipes completely before starting to prevent water damage and potential electrical hazards. Wear safety glasses to protect your eyes from debris, especially when cutting or deburring the pipe. Be mindful of sharp edges on cut pipes.