Torque Calculations for Gland in Cylinders 1

[gordohongo112]

i need to calculate the torque required when fastening a gland into a barrel. (Gland is externally threaded and Barrel tube is internally threaded)

Can i treat this as a joint, where i consider the unthreaded portion of the barrel contacting the gland shoulder a washer?

gland material is ductile iron 65-45-12.
barrel material 1026 steel.

thanks in advance.

 

[gordohongo112]

desertfox: i want to determine a way to calculate a Torque that would be sufficient enough to create a frictional force in the threads and the collar to withstand the maximum axial pushing force created from pressure.

if i were to use this maximum pushing force as the load in the raising power screw equation would this be correct?

 

[MintJulep]

Provided that the thread form is self-locking, any torque will do, and the forces generated by pressure improve the situation.

 

[desertfox]

hi again

for a normal vee thread the effective coefficient of friction is given by Ue = U x (sec B)
where B = half the angle of thread
where U = 0.2 which is the average coefficient of friction for metal on metal.

desertfox

 

[EdDanzer]

The clamping force of the threads is additive to the piston force. These forces and the pressure induced swelling reduce the capacity of the threaded joint. We have gone to acme stub threads for greater durability on this type of cylinder design. Please lubricate the threads. If water can get in the threads will rust and the capacity will be reduced even more and make repair difficult. Locking the head from turning is more important than super tight.

Ed Danzer

http://www.danzcoinc.com

http://www.dehyds.com