Hello everyone, so i am student that still doing my internship in one of oil-well manufacturing company, and the company wants me to do a research about this problem (or may be they just wants me to do this task which probably they have solved this problem),



So as a picture above, there is two pipes connected / jointed in on line, first you can see ring that blue coloured is actually in the first of their design is still not installed but after knows that excessive torque happened, they see that there is need supporting equipment such as ring between it to boost the value of pipe torque.

the variable that known is material of ring,OD and ID of ring without knowing witdth (Length) of ring, my question is may i know how much yield or optimum torque of the ring if i just have those 3 variables : material, od and id ?

which i knew, if there is properties of material known first, maybe the equation i have to use is : T = 16/pi*shear stress*(D^4-d^4/D)
or maybe i use wrong equation ?

Material is l-80 with yield strength is 80.000psi
OD 2-3/8"
ID 1,9"

Probably someone here has opinion about it ?
i need an enlightenment

Thanks before