How to Model Restraint Between Two Pipes in START-PROF

Read about START-PROF pipe stress analysis software

 

Different types of pipe to pipe connections could be modeled with help of internal support (custom expansion joint).

Example 1. Variable Spring Hanger Connected to Another Pipe

Example project file: PipeToPipeConnectionHanger.ctp

For example, we need to model the variable spring hanger, connected to another piping 15-18. The spring is placed in the upper point of hanger. In the bottom point the hanger is connected to pipe with hinge.

The tie could be modeled as pipe element:

  

To model the hinged connection at the bottom of the tie we should add the internal support (custom expansion joint) into the node 17 that is placed on the D/2 from 10-9 pipe axis. Linear restraints should be rigid, and angular restraints should be very flexible.

At the upper point we place the same custom expansion joint but with additional vertical elastic linear restraint that will model the spring flexibility.

The spring tension could be adjusted by adding the cold spring anywhere along the tie length.

Example 2. Pipe Laying on Another Pipe

Example project file: PipeToPipeConnection.ctp

To model the pipe laying on another pipe with resting supports we need to place the jumpers between tho pipes in the points where the resting supports are placed.

Each jumper is modeled by rigid element. The internal support (custom expansion joint) must be placed on the each jumper.

Custom expansion joint should model the resting support behavior. The vertical restraint should be rigid, and all other restraints should be elastic with a very big flexibility.