Use rigid elements to model valves, non-standard valves (3-way valves, actuated valves), pipe-to-equipment connections, jacketed piping, and pipe-to-pipe connections.
For thermal expansion analysis, enable the corresponding option and specify the material and operating temperature.
PASS/START-PROF models rigid elements as pipe elements with an elastic modulus of 2e8 kgf/cm² when no material is specified. When material properties are defined, the elastic modulus is multiplied by 100, making axial, shear, torsion, and bending stiffness 100 times greater than connected pipes.
When rigid element weight is set to 0, fluid, insulation, snow, ice, and wind loads are excluded. For weights greater than zero, these loads are inherited from connected pipes, with insulation weight multiplied by 1.75. Fluid weight, insulation weight, snow, ice, wind, and user-defined uniform loads are averaged from adjacent pipes. This approach supports modeling of 3-way valves and similar components.
Property |
Description |
Name |
Text field for element identification. Elements can be sorted and selected in the project tree. |
Projections\sphere\cylinder1 |
Projections - Input dimensions
as projections on global coordinate axes
DX, DY, DZ. |
Manufacturing technology |
When using GOST 32388-2013, pipe properties vary by type (seamless/welded). This setting determines material database selection for thermal expansion calculations. |
Material |
Select material from the materials database for thermal expansion calculations. |
Operation temperature, Тop |
Temperature for operating mode. Used in thermal expansion calculations. More... |
Uniform pipe weight |
Specify uniform weight distribution for the rigid element. |
To insert a rigid element, select the target node and navigate to: Insert > Rigid Element
To view element properties:
Double-click the element in the 3D view
Select the
element and click 
on the toolbar