How to calculate tensile capacity of thread or coil tubing tool.

[muariya]

Hello Guys, can you help on this Or through some lights to find this.

I have to find tensile capacity for the coil tubing tool. following is the drawing & list

The following are sample drawing not exact drawing

following are connection details

.

Material Min. yield strength is 80000psi

for example from list part "8006-004", Od: 2.875 & id: 1” & connection is 2 3/8 PAC connection.
since pin min. dimension od:2.085in & id : 1.375 in
so tensile capacity is Min. yield strength * min. pin area = 80000 * (pi)/4 ( 2.085^2 - 1.0^2) = 197268 lbs.
&
since box min. dimension od:2.875in & id : 2.406 in
so tensile capacity is Min. yield strength * min. box area = 80000 * (pi)/4 (2.875^2 - 2.406^2) = 155555 lbs.

both pin & box capacity is not matching with 239100lbs
Kindly help me to get tabulated capacity. Any FOS safety should take. What mistake i am doing.
Even if you see, 8006-004, 8006-010, 8006-005 are same OD & same connection size, only id changing. so, I believe they are taking pin connection for finding capacity. i am not getting tabulated values. please suggest what to do.

 

[EdStainless]

Is 239k the Ultimate strength?
My hunch is that they are also a bit stronger connected that taken as individual parts as there will be less buckling and chance for localized issues.

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P.E. Metallurgy, consulting work welcomed

 

[muariya]

No that is tensile capacity. In 1 st picture in last column it’s mentioned. That is tensile strength of that tool.