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Security recommended in Horizontal Directional Drilling.

Security recommended in Horizontal Directional Drilling.

Security recommended in Horizontal Directional Drilling.

(OP)
Good Afternoon.

I have a question.

We need to make a crossing for the Horizontal Directional Drilling method, but for design of the curvature radius.

What is the factor of security recommended?.

I hope your help.

Thanks

P.S. The standard for construccion is ASME B31.4.

RE: Security recommended in Horizontal Directional Drilling.

hfpolo, your question is not clear, but I think what you are asking is what is range for the radius of curvature on an HDD. If you can gove more details (size, lenght, diamter, material, design presusre, DF etc, then it might help.

In my experience the start point for a minimum radius is 600D of the pipe to avoid excessive force on the side of the hole leading to potential for lock up and high pull forces. However what is the actual minimum I don't know, maybe 500D if you really need to for short drills, only that HDD is not normally an exact science in that respect as ground conditions can vary so much as well as length, diamter, outer coating. You also need to check the overall stress levels as the bending force starts to become quite large at 600D and less.

If you mean design in terms of factor of design, most people go for a conservative approach and use 0.6 DF. any corrosion internal or external cannot be repaired and hence you need a bit more 2meat" on your wall thickness. Also as noted above, overall stress levels can be quite high due to the permanent bending moment.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

RE: Security recommended in Horizontal Directional Drilling.

Start with 100ft of radius per inch of steel pipe diameter. Then adjust for ground conditions, length, etc. For PE pipe, radius can be much smaller.

RE: Security recommended in Horizontal Directional Drilling.

In pretty much hypothetical discussions with little information provided some people might forget that cold, hard drill rod steel must be bent to the path curvature (and of course while rotating/"drilling" etc. in the process). Depending on the specifics and machine etc. available or chosen for the drill, and considering the cost of drill rods etc., fatigue of drill rods is a not insignificant consideration.

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