what is the order to connect the pipe

[q0987]

Hello all,

I am interested in how the gas pipe lines are connected in my house.

Please see the attached image.

Assume I need to reconnect the pipes from scratch, Here is my question

What is the order I should put the pipes?

For example, if I install pipe 1 first, then 2, then 3, then 6 and 7.

How can I tighten 5, 4 and 3 at the same time? I am not sure how the bolt 4 works. It seems to me if I tight 3-4 then I will loose 4-5.

Another question is how I can make sure the order of 3-2-6 is in the up-down order. What if I finally can get 6-2-3 up-down order. what else I can do?
What is the trick here?

 

[havasu]

#4 is a union, with reverse threads on one side of the coupling, and should be your last connection. Yes, you start with #1, then the tee (#2) then work down securing #6 and #7, tighten the #3 nipple, then finally the lower half of the union #4, then secure the top half of the union (#4) to #5, then tighten the union center (#4). Another option is to leave #7 until the last connection, so as to allow the gunk and crap to be allowed to fall out before securing.

 

[q0987]

I saw this video [ame]http://www.youtube.com/watch?v=SjNxXk7jZjI[/ame]

where the guy only tighten the lower and upper parts of the union. I never saw him tighten the center part.

Is there anything wrong?

Thank you

 

[havasu]

There is nothing wrong with what I saw from his installation, but I can assure you he tightened the union either prior to or after the installation. The video did not show what he used to complete the installation, and I can only presume he used a flexible line.

 

[smithrick420]

Hello all,

I am interested in how the gas pipe lines are connected in my house.

Please see the attached image.

Assume I need to reconnect the pipes from scratch, Here is my question

What is the order I should put the pipes?

For example, if I install pipe 1 first, then 2, then 3, then 6 and 7.

How can I tighten 5, 4 and 3 at the same time? I am not sure how the bolt 4 works. It seems to me if I tight 3-4 then I will loose 4-5.

Another question is how I can make sure the order of 3-2-6 is in the up-down order. What if I finally can get 6-2-3 up-down order. what else I can do?
What is the trick here?

steps of rejoining gas pipe in your house:

1 Extend your existing gas line by fitting the valves and pipe lengths you need to add a gas line that will reach your new appliance.

2 Use a flexible pipe to connect the end of your new gas line to the appliance.

3 Spread a mixture of water and dish liquid over each seam in your gas line. If bubbles appear, you have a leak. Unscrew that section, strip off the pipe glue, and reattach with new sealant.

4 Turn the gas back on by returning the valve to parallel to the incoming pipe. Test your appliance to ensure the gas is flowing properly.

 

[PioneerPlumber]

I find this whole thread a bit unsettling...

Go to Home Depot and play around with those same fittings. That should answer all of your questions.

It should be pretty clear as to which area to start with and where to finish.

The purpose if the union is to join two independent sections of piping together. Th last connection will be the union. (With pipe dope on the inside face I hope...)

 

[Caduceus]

note: sealant is not to be used on the face of the ground joint of a union. threads, yes. face, no.

 

[PioneerPlumber]

Any connection that seals between two metal surfaces (brass, copper, steel, etc) including compression, flare or unions needs to have pipe dope applied to the face or surface area that is sealing the joint. The threads of a union do not seal the joint, they draw the two separate pieces together.

I also dope the threads which allows the fitting to be more easily disassembled in the future.

I understand that "by design or in theory" you are not required to do so and that the design of the fitting should not need it, but lets be real here... Any plumber with experience knows this is needed.

Thoughts?

 

[johnjh2o]

Any connection that seals between two metal surfaces (brass, copper, steel, etc) including compression, flare or unions needs to have pipe dope applied to the face or surface area that is sealing the joint. The threads of a union do not seal the joint, they draw the two separate pieces together.

I also dope the threads which allows the fitting to be more easily disassembled in the future.

I understand that "by design or in theory" you are not required to do so and that the design of the fitting should not need it, but lets be real here... Any plumber with experience knows this is needed.

Thoughts?

I have been doing it for 50 years and never used pipe dope on ground joints.

John

 

[stevemachine]

If its residential you can blow through a straw more pressure than what comes out of your gas lines. 7" w.c is so minimal that I've never had to dope them. I don't have a ton of experience by any means but in 3 1/2 years I've never had an issue, but that's just my 2 cents

 

[stevemachine]

However if its a pressurized line like domestic water or a heating system I've done it before if they've leaked, and I had to disconnect and reconnect the union.

 

[Caduceus]

It's not an issue of whether or not the threads or face give the seal. Dope on the threads is just to run the nut smoothly across the threads.
A metal to metal ground joint gets a secured seal through compression and friction on the machined faces. Pipe dope, by design, reduces the friction between the faces and may also mask imperfections or inadequate seating. After some time the pipe dope will dry, shrink and expose the leak that was undetectable at the time of testing.
I have had leaky unions (on gas and water distribution) and upon inspection can see minor defects that caused the leak. Using pipe dope may have left it undiscovered.
I know many plumbers who DO use it on unions and flare connections, I just choose not to because of the reasons stated above. I've heard the defense "I've been doing it for 20 years and never had a problem." so many times, it just goes through one ear and out the other. "...never had a problem." only translates into "...when there was a problem, somebody else fixed it."
Not hatin' on anybody, these are just my experiences.

 

[PioneerPlumber]

I wouldn't have expected a response from like that from you John. A large portion of the work I do is with gas. I can't even count the number of leaks I've found/repaired due to unions. Regardless of the pressure and or fluid/gas running through it.
7" is not a lot by any means, but why risk it?
Is anyone suggesting that the proper type of dope would be harmful to a ground joint connection? (Excluding over application or potential cause of an obstruction as this would be human error...)

I guess I'm
Just baffled at these responses...

 

[PioneerPlumber]

Caduceus,
I actually just read your last post after drafting my previous response.
I see your point, and I agree with what you are saying to an extend. I acknowledge your point and the dangers of masking an imperfection or installation error along with the risk/safety factors.

I inspect the condition of every fitting prior to installation as I'm sure you do too. The repercussions and effort required to address something like that after its installed can be costly for many reasons.

My point is, if the union or any other ground joint is not damaged or cracked or scratched, what is the harm of applying something extra to help ensure no leaks?
Also, I believe the use of dope to assist in the tightening process and allow for tighter face to face contact.

Everyone's experience with plumbing and what they've seen/encountered or repaired will effect their opinion. The majority of all the leaking ground joints I've seen (regardless of age) have not had pipe dope applied. Almost all that have had dope applied have not...

Please respond... Am I missing something? My ultimate position is to do plumb the best and safest way.

All due respect.
Daniel

 

[Caduceus]

First let me apologize to q0987 for the way we hijacked this thread. Unless you find it an entertaining read, just tell us to scram and we'll continue elsewhere.
I guess a fair way to explain this, Pioneer, is through past experiences.
I have responded to many gas leak calls in homes. Whether the previous work was done 6 months earlier or 6 years earlier, and a leaking union was the culprit, I would find the union threads and face coated with pipe dope. I cannot recall ever finding a leaking union that was installed without pipe dope. If anything, they were still sealed well and a bit tough to undo to get to other leaks in the piping system.
Lets all agree that at some point any union can leak with or without pipe dope on it. If by adding pipe dope you increase, by the slightest margin, the risk of a leak as opposed to not using it what would the logical approach be?
I believe I've posted before about bad unions on the market. If a union doesn't seal without dope, why would applying dope be an acceptable permanent solution to a poorly machined product. If you have ever installed CSST gas lines I'm sure you wouldn't disassemble the union and apply dope if it leaked. You would make a new cut and reassemble. Same with steel and brass unions. IPS threads run deeper and tighter in a female fitting and sealants reduce some of the friction so that the mating can be completed more easily, but at no time compromises the seal. But if the threads were cut too deep, you wouldn't just apply 10 layers of teflon tape to fill the gaps, right. A newly threaded piece would be needed.
I don't know if this will change the way you install from now on, but it may bring your attention to it in the future and if you notice the same situations that I have noted above, maybe it will seem more reasonable.
Believe me, I've had a lot of plumbers try to beat me up on this subject over the years but I don't sweat it. Healthy debate keeps us on our toes and exercises our brains.

 

[johnjh2o]

My reasoning for not using pipe dope is unions are ground joints. They cannot be dented or scratched. We all know what we do with our pipe dope. We use a brush to apply it to pipe threads, the brush gets dropped in the dirt then placed back in the can along with the dirt or whatever else got stuck to it. Then you put the dope along with the dirt on the union face and then tighten the union grinding the dirt into it.

John

 

[Caduceus]

Guess I could have kept it short and simple like that, John. Another good point. I got a good laugh, at my own expense, on that one.

 

[PioneerPlumber]

First off, I appreciate the time you have taken to discuss this topic and share your thoughts. I find this thread VERY interesting and educational. Just by reading your response, i can tell you are educated which enhances the validity of your opinions. Everything you are saying makes perfect sense. And no, I would never just apply dope to the face of a poorly cut piece of CSST.

I understand that in a perfect world, with a perfectly manufacturered fitting and under perfect circumstances, the fitting should seal if installed properly.
How often is this the case? If for example, you have installed a union without dope and there are no leaks, what's to say that it will not start to leak in the future? What if by using dope it prevents an otherwise unnoticeable scratch from causing a future leak?
I ping every union with a punch. (Gas only) I do this because I am afraid of future leaks due to expansion, contraction, vibrations etc.
You stated that you can not recall ever finding a leaking union that did not have pipe dope... My experience has been almost the exact opposite.

You also stated that if adding pipe dope adds even the slightest increase for a leak, why would you use it? Again, my thoughts are almost the exact opposite... If there is even the slightest chance of a union leaking without dope, why wouldn't you use it? I still can't grasp how it would be better not to use it. And no, I would not use contaminated with dirt or debrit. (Same goes for flux, glue etc.)

I understand that I do not and will never know everything about plumbing. I also believe anyone who says they do is an idiot. I appreciate your thoughts because I understand that There may be a different way of doing something that is better than I have always looked at as "the best way"
We need to learn from each other as much as possible because one day we will die. And everything we have been tought or learned on our own will be gone along with us.
We are a dieing breed...

I will look at this with an open mind and I sincerely appreciate your feedback!

And yes, I apologize if we have offended anyone for high jacking their post... Haha

 

[PioneerPlumber]

By the way, I am 32years old and plumbing has given me the chance to provide well for my family. I am the service manager for a company here in Arizona. One of my driving forces behind the interest in this topic... I put on a meeting for all of my 20something employees every week and I feel I owe it to them and my company to be teaching the right way. The company I work for has the knowledge and experience to handle difficult projects. Everything from high end remodels, new homes, master meter installations and service to the smallest service call. I have even re-piped hospitals.
I am only 32. Very young. There is so much more to learn and I want to continue to absorb anything else I can be taught. It's gotten me this far.

Thanks again.