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PIPE shoe length 3

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DrunkEng

Mechanical
Mar 27, 2015
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HI all,

How pipe shoe length is decided for pipe shoe with stopper.Currently we are using 650mm length for pipe shoe with stopper welded to it for 50mm insulated pipe 10".
pipe_shoe_hkamr2.jpg

thanks
 
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Just experience, custom and practice (and the drawings from the last job the piping designer did...). There is not usually too much science or calculation about it I'm afraid.

Too short and the moment on the pipe is high and its small fillet weld might fail. Too long and you've used more material and welding.

As a ROT - for this type of stop you want around 3 x OD, but it becomes too tedious to change this for every pipe size so you tend to get groups of sizes together.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
You do not mention the design conditions of the piping, especially the thermal loads on the pipe.
The thermal load difference between pipe and support will introduce additional stresses at the connected area and surrounding on the pipe. If this the thermal load difference between pipe and support does not happen, you do not have any problem with the support as long as the support and its connection onto pipe designed adequately for the other type loads.

Shorter supports are better, however the thermal expansion on the pipe at pipe support needs to be considered on the supporting structure. However companies need to make kind of standard support library not to design for every occasion or to give some kind of guidance to the designers for the support selection process.
 
DrunkEng,
Your question = How pipe shoe length is decided for pipe shoe with stopper?
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Terminology - Stopper is a very confusing term. I do not think it has a common understanding. You are meaning "Restraint". Restraints come in two basic types: Linear and Lateral.
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The Linear restraint prevents movement in the direction (longways) of the pipe run. This type of Restraint is normally called an "Anchor". An Anchor can be created at least three ways; by welding the Shoe base to the top flange of a steel pipe support or the steel Plate embedded in the top of a Concrete pipe support or by attaching steel "Clips" to the bottom of the Shoe and against the side of the pipe support.
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The Lateral restraint prevents movement in the side-to-side direction of the pipe run. This type of Restraint is normally called a "Guide".
All piping subject to Thermal Expansion (large, small, hot or cold) require consideration for the amount of expansion and the type of Shoes, Anchors and Guides.
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Shoe Length - The Shoe length you are using may be okay for your current application but do not automatically consider it okay for the next project. You seem to be using the 650mm shoe for all Shoes that is the right thing to do. It means you can have a supplier make them in mass at a cheaper price and it also helps cut costs in the field when placing them on the pipe and support because the field crew does not have to look for custom length shoes for each pipe support location.
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Shoe Placement - The placement of all shoes (at installation) should be in the center of the pipe support with the pipe at ambient temperature.
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Yes, I know this is more than you needed or wanted. However, your question is posted on a popular website and both your question and answer will be read by many others. Maybe some of these others will benefit from the little extra I have included.


Sometimes its possible to do all the right things and still get bad results
 
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