Stress Report Table for PUR (polyurethane foam) Insulation

Insulation stress is calculated only for straight pipes, bends and tees with polyurethane insulation in buried elements according to EN 13941, EN 253 and GOST 55596 codes.

Strength is assessed based on equivalent and tangent stress acting along and perpendicular to the pipe axis. For more detailed information, see Polyurethane (PUR) Insulation Stress Analysis.

If strength conditions are not met, the corresponding cell in the table will be highlighted in red, and the last column will display the error number, the text of which can be read by hovering over it with the cursor. When printed, the error and warning messages can be found below the table. If strength conditions are met, the "notes" column remains empty.

Properties

Property

Description

Perpendicular tangent stress

Circumferential shear stress due to pressure from above-laying backfill soil, τxy see Polyurethane (PUR) Insulation Stress Analysis

Allowable perpendicular (circumferential) tangent stress

Allowable perpendicular (circumferential) tangent stress

Longitudinal tangent stress

Longitudinal shear stress along the pipe axis due to friction of pipe and soil during longitudinal thermal displacement, τyz see Polyurethane (PUR) Insulation Stress Analysis

Allowable longitudinal (along pipe axis) tangent stress

Allowable longitudinal (along pipe axis) tangent stress

Equivalent stress

Equivalent stress see Polyurethane (PUR) Insulation Stress Analysis

Allowable stress

Allowable stress

Notes

No.

Note

Description

N287

Tangent stress exceeds allowable

Tangent stress in insulation exceeds allowable

N290

Equivalent stress exceeds allowable

Equivalent stress in insulation exceeds allowable. Laying depth should be reduced

N289

Pipeline loads from soil pressure must be removed

Error occurs when pipe wall stability is lost under surrounding soil pressure, for example, in  vacuum elements. In this cases, wall thickness should be increased, laying depth should be decreased, or soil weight should be decreased

Menu Access

After analysis: Output > Insulation Stress