Pipe supports

[Kuhuh]

Can someone help me figure out what size all thread I can use to support pipes that are producing 1506# shear I want to use a 20' piece and the force would parallel to the length of the rod. Needs to be galvanize or 316 rod. The rod would be attached to a 3"x3"x1/2" angle rod that is attached to the pipe to keep it from sagging. Do I look for tensile strength of the rod? if so I know its like 125,000 Psi but that doesn't seem right because it doesn't change on the size. I am thinking a 3/4" all thread will be good enough.See drawings

 

[ishvaaag]

Is it like if you want to impart some prestress to the blue rod to relieve the pipe of most of the effects of flexural action, and then you are asking for the adequate rod material, prestress, and sizing?

 

[IFRs]

You should be using the yield strength of the rod in psi times the cross-section area of the thread root in square inches. When multiplied together you get pounds. Reduce the diameter by your corrosion allowance before calculating the area. For 4 inch pipe, 3/4 inch rod feels quite strong enough to me.

 

[Kuhuh]

This what I did

Test pressure is 125 psi

F(of Pipe)= A*P=1594.5
since there is 4 pipes assume 5th as 4" even though 2"
F( of pipe)=7972.5


Axial stress=F(of pipe)/A(3/4" tie Rod)=23,587.27 <36,000 ok but not great

so try(1" tie rod)

Axial Stress=12531 <<36 much better

is this procedure seem ok until I get the S.E. to give me stamped calcs. I just want to show the inspector since we are running behind schedule. see photo of 3d model of this

 

[Kuhuh]

oops

 

[ishvaaag]

You are passing pressure forces eccentrically to frame members. It is not clear from your sketch if some end of the pipes is just closde blind, and the pipes some way supported in the frame members, and if at the other end some piston pass forces between inner pressurized fluid and the framing providing support.

From the frame analysis viewpoint (any rod included), you may substitute your pressurized pipes by their weight properly distributed to the support points, and the effects the pressurization passes to the frame. Once that is done analysis proper can be reasonably started, and so the effectivity of any eccentrical rod holding any tension that may appear can be then reasonably ascertained.