Asked by: Dayanna Fores
Asked in category: automotive, auto parts
Last Updated: 11th Jun 2023

How can you tighten a union fitting

Attach the larger central nut to the union's end nuts by hand to one pipe end. Secure it with a crescent wrench. Attach the other end nut of the union to the pipe end and tighten it again with the wrench.

Afterwards, you might also wonder, "How do I tighten plumbing fittings?"

5 Tips to Tighten Plumbing Fittings

  1. It's OK to be tight, but not too tight. The pipes don't have to be snagged too tightly to allow water to flow freely.
  2. Do not strip the threads. Most plumbing fittings have large bolts.
  3. Righty tighty, Lefty loosey.
  4. Plumber's Tape.
  5. Keep your plumbing fittings warm.

Also, when is a union fitting appropriate? A coupling is a solid fitting that has female threads at both ends. This is used to join two lengths of pipe that can be turned and are not locked together. When you want to join two pipes that cannot be turned, a union is necessary.

This is where you can see the direction that unions are heading.

It is a good habit to develop. It doesn't really matter most of the time, but it could in certain applications (e.g. steam, high-velocity liquids, etc.) that the service will cause the union to be eroded.

How can you stop a union leaking?


  1. To melt solder, heat the joint that is leaking if the union is not connected to the solder joint. You can remove the union, spread new flux, and resolder it.
  2. If the union involves joining copper and galvanized-steel pipes, it should be dielectric.