# Union Facts?



## ILPlumber (Jun 17, 2008)

That got your attention, didn't it:laughing:

I had an employee tell me today a union was a directional fitting. The flow should go from the "spigot" half into the "hub" half....

I think this is pure bunk. Can anyone supply me with facts that unions, are in fact directional?

As long as it doesn't leak, I can't see how a union would "know" what direction the water is flowing through it? 

I also see no turbulence issues. As it is smooth on the inside when made up. Except for the small ridge in the middle that is equal on both halves.

I hereby call on the power of the PZ. What say you?

Remember. Saying "That's the way we've always done it" is not a fact.:laughing:


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## Optimus Primer (May 20, 2009)

Never heard that. But I try to put the nut that holds it together to where its always on top so it doesnt fall down. We had a guy at our shop that had half the employees believing that these 3 inch pvc dwv couplings were directional because the stop had a bevel on one side. So I emailed the manufacturer and explained what he said and they replied that there was no such thing. one helper even told me thats why you see those tits on the couplings, that meant they were directional. I said all pvc fittings have those. It's from the injection mold.


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## Optimus Primer (May 20, 2009)

plus if it's directional, where is the arrow?


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## Airgap (Dec 18, 2008)

I was told as an apprentice they were directional. The flow was supposed to go to the seat side, but I can't say whether or not i believe it really matters much. I still install them that way cause that's how I was taught...


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## SlickRick (Sep 3, 2009)

Ball valves are directional also. So they can be taken apart under pressure. :blink:


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## ILPlumber (Jun 17, 2008)

slickrick said:


> Ball valves are directional also. So they can be taken apart under pressure. :blink:


No. But I see lots of unions put on the incorrect side of a copper sweat ball valve.

Now, back to topic. I want facts. I believe there are none.


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## 422 plumber (Jul 31, 2008)

There was a traveler out of either Louisiana or Alabama that called unions "three piece come togethers." He was serious.


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## wundumguy (Apr 3, 2010)

I remember being taught in first year that a union is directional. I don't remember if it was in the instructor's lecture, or if it was in the UA textbook: Pipe, Fittings, Valves, Supports and Fasteners. But they also instructed us to do any work according to the preferences (and there are some I think are kinda far fetched) of the journeyman to whom we're currently assigned.


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## Phat Cat (Apr 1, 2009)

No facts, but my husband heard the same thing long time ago that they are directional.


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## MIbassmaster (Mar 16, 2010)

Dielectric unions are used on both inlet and outlet. :blink:


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## ILPlumber (Jun 17, 2008)

jjbex said:


> There was a traveler out of either Louisiana or Alabama that called unions "three piece come togethers." He was serious.


Double Nut Coupling


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## Bollinger plumber (Apr 3, 2009)

I had a plumbing inspector tell me that unions were directional. I ask him to prove it to me before I changed them all. Never said another word to me about it. Guess he never found the proof.:whistling2:


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## Bill (Jun 17, 2008)

Never heard of a union being directional. Someone is trying to be super intelligent.


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## PLUMBER_BILL (Oct 23, 2009)

Bill said:


> Never heard of a union being directional. Someone is trying to be super intelligent.


Yes a union is directional. I was instructed by an apprenticeship teacher 
55 years ago to that fact and he had the reason. The union on a vertical 
pipe is always installed so that the union ring is on the top. That way the ring cannot fall to the floor which means in some cases you would have to crawl down off a ladder to get it. No answer for a horizontal pipe.


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## Bollinger plumber (Apr 3, 2009)

PLUMBER_BILL said:


> Yes a union is directional. I was instructed by an apprenticeship teacher
> 55 years ago to that fact and he had the reason. The union on a vertical
> pipe is always installed so that the union ring is on the top. That way the ring cannot fall to the floor which means in some cases you would have to crawl down off a ladder to get it. No answer for a horizontal pipe.


But that was before the invention of duct tape to hold it in place :laughing:


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## Tommy plumber (Feb 19, 2010)

I had a guy try to tell me one time that backflow prevention assemblies were directional, he even showed me an arrow on one, what an idiot!:laughing:


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## njoy plumbing (May 19, 2009)

I'm right handed, the nut is always on the right. Right?


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## ILPlumber (Jun 17, 2008)

I usually put the nut on top. There is nothing worse than nut loss:whistling2:


If your making up a 4" union on a vertical pipe. You are glad the nut is one top. :yes:


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## futz (Sep 17, 2009)

I was taught by some journeyman "expert" long long ago (lost in the mists of time ) that unions were directional. I never really believed it, but I got in the habit and can't break it. The nut is always upstream for me.


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## Protech (Sep 22, 2008)

Your 3 handle shower valve installs must look neat :laughing:



Matt said:


> I usually put the nut on top. There is nothing worse than nut loss:whistling2:
> 
> 
> If your making up a 4" union on a vertical pipe. You are glad the nut is one top. :yes:


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## ROCKSTARPLUMBER (Dec 14, 2008)

Damn yankee is probably talking about a DI electric union.:laughing:


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## Don The Plumber (Feb 14, 2010)

Every union I ever seen, always had the nuts at the top


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## grandpa (Jul 13, 2008)

Don The Plumber said:


> Every union I ever seen, always had the nuts at the top


\

Is that comment referring to a mechanical pipe connector, or to the local hall!!!!!!!!!!!!!!


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## Don The Plumber (Feb 14, 2010)

grandpa said:


> \
> 
> Is that comment referring to a mechanical pipe connector, or to the local hall!!!!!!!!!!!!!!


I'll never tell.:yes: :no: :yes: :no:


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## Herk (Jun 12, 2008)

I've never heard that unions were directional, but it is prudent to install them so that they are serviceable. You need room for wrenches. It makes sense to not put them upside down so that the collar doesn't drop to the floor but think of a dielectric union (which is directional in regard to the copper/iron connection) installed on a galvanized drop.

We've all cussed installers who put unions where they can't be reached.


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## jc60618 (Jan 24, 2010)

Herk said:


> I've never heard that unions were directional, but it is prudent to install them so that they are serviceable. You need room for wrenches. It makes sense to not put them upside down so that the collar doesn't drop to the floor but think of a dielectric union (which is directional in regard to the copper/iron connection) installed on a galvanized drop.
> 
> We've all cussed installers who put unions where they can't be reached.


 
:laughing:Or we've all cussed installers that put ball valves after the union:laughing:. So when you want to take the equipment apart you have no way to isolate the water.


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## TheSkinnyGuy (Sep 15, 2009)

Tommy plumber said:


> I had a guy try to tell me one time that backflow prevention assemblies were directional, he even showed me an arrow on one, what an idiot!:laughing:


I love the money when I have to clean up after the smart guys that don't believe in following the directional arrows.:whistling2:

As far as unions being directional, I could see why you would make that arguement, but as far as I see it its not true.


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