Snubbers reduce displacements, stresses, and support loads during seismic events. Two types available: hydraulic and mechanical.
Snubbers allow thermal displacements and maintain piping flexibility. For rapid occasional loads, snubbers lock to form rigid restraints. They remain flexible for sustained and thermal loads but lock for dynamic loads, then unlock when dynamic loads dissipate.
Snubbers lock during seismic analysis, dynamic analysis, and occasional operating modes with "Snubbers Active" enabled. They unlock in all other operating modes, force-based modes with "Snubbers Active" disabled, and for snow and ice loads. Wind load behavior depends on "Active" flag in project settings.
PASS/START-PROF snubber objects include 6 restraints: 3 linear and 3 rotational.
Property |
Description |
Name |
Element name. Check to display in 3D view. |
Weight |
Support weight (pipe-attached portion). Applied to attachment node. For building structure allowable loads, calculated load includes piping plus support weight. For support-only allowable loads, either omit support weight or increase allowable load by support weight value. |
Restraint Type |
Rigid double-acting or spring. "No" indicates no restraint. |
Element Local Axes |
Use local axes of selected element as restraint local axes Xm, Ym, Zm. |
Local Axes |
Unchecked: allowable loads set for global axes (X,Y,Z). Checked: allowable loads set for adjoining element local axes (Xm,Ym,Zm). All restraints must be perpendicular.
Select "other" to input custom restraint direction.
Define restraint direction with three angles between restraint vector and global coordinate axes. Enter minutes as decimal degrees (two decimal places). Example: 30.25 = 30°15'. Positive angles require no "+" sign. More...
For single-directional restraints in local coordinates or gaps, specify element whose local axes define restraint direction. |
Restrain Displacement Along Axis |
Select displacement restraint direction. +/- irrelevant for double-acting and spring restraints without gaps. With gaps in double-acting restraints, select positive direction. For single-directional restraints: +X restricts positive X-axis displacement, -X restricts negative X-axis displacement. |
Restrain Rotation Around Axis |
Select rotational restraint direction. |
Flexibility |
Spring restraint flexibility. |
Check Allowable Loads |
Enable to automatically check allowable loads against analysis results. PASS/START-PROF displays warnings for exceeded values. |
Allowable Load |
Allowable load in restraint direction. |
Select the desired node, then use: Insert > Insert Restraint > Snubber
