Dismantling joint

Greetings, 

To be honest I have never seen this type of fitting before and I am trying to understand the usage:

From my research, Dismantling Joints are particularly suitable for simplifying the installation & removal of various piping components. The plus and minus dimension specified on the label are the maximum and minimum amounts of movement available to take up any site tolerances.

Therefore this fitting is to help when the piping is not correctly fabricated. In order to model this fitting, we need to clearly identify the movement, restraining directions, and flexibility / stiffness. 

After this joint is assembled:

1. Can the joint move axially? 

If yes, how far before it stops

If no, what amount of stiffness is restraining it

2. Can the joint move laterally?

If yes, how far before it stops

If no, what amount of stiffness is restraining it

At this moment, this looks like and functions like a tied expansion joint and would suggest modeling as such. See WIKI here, select the hyperlink for   "1.b Different Types of PIPING Components". Then select the hyperlink for "c. Flexible / Expansion Joints ". On this page the click on the hyperlink for "Flexible Joints" in the table, and follow the instructions to review and actually perform the following modeling example for:

• Model 1: Tie rods modeled as a single two-point support
• Model 2: Tie rod assembly modeled as beams and two-point supports

I suspect that either of these approaches would be appropriate for modeling a Dismantling Joints. You, the user, would need to figure out / calculate what stiffness should be entered into the various fields of a flexible joint and then that by the tie rods. Just think about what each component is doing and which is carrying the load of the assembly.

Otherwise, if you believe that a Dismantling Joint is as strong as a normal Flanged joint, then model as a flange joint with a rigid section between 2 flanges. 

Regards,
Mike Dattilio
Design Analysis Engineering Group
Senior Analyst Bentley Systems Inc
=============================================================================

Greetings, 

To be honest I have never seen this type of fitting before and I am trying to understand the usage:

From my research, Dismantling Joints are particularly suitable for simplifying the installation & removal of various piping components. The plus and minus dimension specified on the label are the maximum and minimum amounts of movement available to take up any site tolerances.

Therefore this fitting is to help when the piping is not correctly fabricated. In order to model this fitting, we need to clearly identify the movement, restraining directions, and flexibility / stiffness. 

After this joint is assembled:

1. Can the joint move axially? 

If yes, how far before it stops

If no, what amount of stiffness is restraining it

2. Can the joint move laterally?

If yes, how far before it stops

If no, what amount of stiffness is restraining it

At this moment, this looks like and functions like a tied expansion joint and would suggest modeling as such. See WIKI here, select the hyperlink for   "1.b Different Types of PIPING Components". Then select the hyperlink for "c. Flexible / Expansion Joints ". On this page the click on the hyperlink for "Flexible Joints" in the table, and follow the instructions to review and actually perform the following modeling example for:

• Model 1: Tie rods modeled as a single two-point support
• Model 2: Tie rod assembly modeled as beams and two-point supports

I suspect that either of these approaches would be appropriate for modeling a Dismantling Joints. You, the user, would need to figure out / calculate what stiffness should be entered into the various fields of a flexible joint and then that by the tie rods. Just think about what each component is doing and which is carrying the load of the assembly.

Otherwise, if you believe that a Dismantling Joint is as strong as a normal Flanged joint, then model as a flange joint with a rigid section between 2 flanges. 

Regards,
Mike Dattilio
Design Analysis Engineering Group
Senior Analyst Bentley Systems Inc
=============================================================================