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plumbing union

I am trying to figure out how to figure the lenght of pipe i need to finish a plumbing project.

I am working with 1 1/2 water pipe. I have 2 legs that i want to connect together. The distance between the elbows is 3 feet.
Each leg has an elbow and both are straight opposite of each other.

I want to install a union between the legs.

How much gap is needed between the union halves to properly seal the union?
I know i will need some nipples.

Re: plumbing union

There should be no gap between the union halves.


Re: plumbing union

Thank you John. NOW. How to figure the lenght of pipe that i need for each side and the union in the middle?

Re: plumbing union

You say your overall length is 3', add 4" for the four joints to make up then deduct the overall length of the union. (which can vary depending in the union your using) Half of that will give you the size of each nipple needed to place the union in the center.


Re: plumbing union

There are different ways of doing this.

One way is: If one of the elbows could be moved (by undoing the strap that's holding the pipe in place), you just install the union in the middle and then re-fasten the elbow.

Measuring the two halves will give you at least one half which is not a standard size, requiring a custom threading.

Re: plumbing union

Sounds like you are in over your head, I would call a Plumber.

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