Tees vs Weldolet in new piping system 2

[lookintomyeyes]

After receiving a price quote for (water) piping, I noticed that weldolets were priced cheaper than tees. However, (to my knowledge) tees are simpler to install on a (new) system than weldolets.

Therefore my question is a rather general one of whether it is ever useful/worthwhile to install a weldolet over a tee on new piping.

 

[BigInch]

My rule of thumb is when there is a standard size tee, use the tee. If the branch from the header is smaller than any std tee available, use a weldolet. I believe this is a better long term stress solution.

Going the Big Inch!

http://virtualpipeline.spaces.msn.com

 

[pennpiper]

I respect what BigInch has said and for most higher pressure and temperature Steam or Hydrocarbon systems I would go with what he said.
However you said that you have a water system. So I suggest you consider the following.

Size-to-Size - use a TEE
Size-to-One Size Reducing - use a TEE
Size-to-Two (or more) Size reducing - use a Weld-o-let

 

[BigInch]

Well...since I'm basing that from a pipeline background, I did actually mean it more in regard to soil stresses rather than internally generated stresses.

Going the Big Inch!

http://virtualpipeline.spaces.msn.com

 

[rconner]

If a welded outlet is furnished already on a piece of longer pipe from the manufacturer, I think it might be very hard to argue at least in that case that "tees" are simpler to install than that system (as of course it might not be necessary with that system to make-up/assemble the two extra? tee joints in the field -- just install it like another piece of pipe, and at least some joints are thereby eliminated). This of course assumes the station of the pre-welded outlet could be reasonably located or readily adjusted with pre-fabricated piping.
If on the other hand the outlet/weldolet must for some reason be welded in the field, as I suspect may be the case with what you are talking about, this of course requires equipment/expertise and everything that goes with doing that right in-situ. Some sort of readily assembled, pre-located "tee" joints on the other hand may not require such field-welding equipment/expertise etc., and in that case maybe it could be argued that that tee system is "simpler to install".
I think there are perhaps different ways of looking at these issues.

 

[BigInch]

If you're doing code welding, a weldolet on top is easier to X-ray than a full tee, so really if you want to make conjecutre, it depends a lot on what you're doing as to what you choose to do it with.

If he's just asking rule of thumb what to use, I think he's basically got it.

Going the Big Inch!

http://virtualpipeline.spaces.msn.com

 

[lookintomyeyes]

BigInch, it is a pressure piping system that falls under B31.1, so the xray consideration could be a valid one.

Also though, if the "rule of thumb" was directed at me:
I'm female.

 

[BigInch]

You know I thought about and actually almost wrote (s)he.

Anyway, the more you say about what you want to do in the original post, the better and the sooner you'll get a good answer.

Going the Big Inch!

http://virtualpipeline.spaces.msn.com

 

[lookintomyeyes]

I'll keep working on that, and in the meantime, thanks for you patience. As a basically new engineer with 1 year + 2 summers worth of experience, I have alot to learn, so I try to learn the "unwritten rules" of engineering as well as those well-established in handbooks and guides.

 

[BigInch]

They specifically don't write the unwritten ones down anywhere, so we can change them if we need to.

Going the Big Inch!

http://virtualpipeline.spaces.msn.com

 

[pennpiper]

LITME,
You have shared with us that you are new to the piping field. Not a problem. There are lots of us old-timers who are ready, willing and able to help you (and others).
For starters I suggest that you have a look at the following website,

http://www.pipingdesigners.com

There is a lot of information there under "Training", "Tips", "Tools", "Standards" and the "Forum"

Good luck and let me know if I can be of help

PennPiper (aka Jop)

 

[lookintomyeyes]

Thanks Pennpiper.
I think pages of that site will be printed off and put in an "HELP!" Binder of reference material like several of my colleagues own.

I work in hydroelectric generation, but find myself drawing to "auxiliary" systems like piping and HVAC - I think it is because they are more transferable should (heaven forbid) something happen to the government-owned company I work for.

 

[NozzleTwister]

lookintomyeyes,

I basically agree with Pennpiper except that I think there are more things to consider and more options.

Besides a reducing tee and a weldolet, consider also a stub-in for low pressure applications or a stub-in with a reinforcing pad. This may be more economical for branches larger than 6" or 8".

While reducing tees are available down to the 1/2 the run diameter, I don't see them used very often for more than a one size reduction.

If you're driven by economics, consider the total installed cost and fitting availability. Other than the price of the fitting and materials, other costs include the cost of the welding, x-rays and heat treat. These costs and requirements will change with size and materials. For example, an 18" WOL on a 36" header is a big heavy chunk of metal that requires a lot of weld.

Good luck,


NozzleTwister
Houston, Texas