ASME B16.9 Elbow

Manufactured without longitudinal welds, unlike welded elbows. ASME and EN codes treat forged elbows, induction bends, and welding elbows identically for stress analysis.

Maximum bend angle is 90 degrees (More...). START-PROF performs wall thickness checks per Russian codes but not ASME for this bend type.

Properties

 

Property

Description

Name

Element identifier. Enable to display in 3D view.

SIF

Displays h-factor, stress intensification factors, and flexibility factors.

Radius, R

Mean bend radius (0.5D)

Get properties from matching pipe

Inherits properties from connected pipe element.

Calculate weight automatically

Calculates weight as torus volume using adjoining pipe wall thickness.

Weight

Bare elbow weight (includes flanges). Excludes insulation and fluid content. Set per standards without overload factors. Fluid and insulation weights with overload factors calculate automatically from adjoining pipes.

Longitudinal Weld Joint Efficiency Factor, E

Longitudinal weld joint efficiency factor. More...

Calculate angle automatically

Bend angle for flexibility factor (k-factor) calculation in certain codes. Enable by default.

Disable when modeling supports on split bends. Specify the full bend angle, not individual segment angles.

Angle

Manufacturing technology

For seamless pipe (ASME B31.1, B31.3, DL/T 5366-2014), Wl=1.0. For electric-welded pipe, Wl from database. More...

GOST 32388-2013 uses different material databases for seamless/welded pipe.

Material

Material from materials database

Presence of flanges

Select number of flanges. Flanges are rigid elements that limit cross-section ovalization. Affect flexibility and stress intensification factors..

  • none - welded connections both ends

  • one flange - one flanged end, one welded end

  • two flanges - flanged connections both ends

Position of welds

Weld orientation relative to bend plane. See fig. 1

Nominal wall thickness, S

Nominal (as-built) wall thickness

Mill tolerance, С1

Manufacturing wall thickness tolerance. More...

For RD 10-249-98 analysis (section 3.3.2.8), input three tolerance values (С1=С11+С12): extrados, neutral axis, and intrados, with difference equal to С12. More...

Corrosion and wear allowance, С2

Corrosion/erosion allowance for wall thickness. More...

Do not check internal bend wall thickness

Per RD 10-249-98 section 3.3.2.8, for extruded elbows or induction bends with axial preload, set c12 allowance from 0.05s to 0.1s for extrados (sR1) and 0 for intrados (sR3). Internal bend analysis is omitted.

For extruded elbows with perpendicular weld at mid-length, set c12 allowance 0 for intrados and 0.05s-0.1s for extrados. Internal analysis omitted due to wall thickening exceeding K2 factor.

Hand-lay

Select for manually wound elbows.

Stress correlation along two axes, r

Per ISO 14692 section 7.10.

Qualified stress, qs

Blank field uses value from material database.

Per ISO 14692 section 7.8.

Internal protective layer thickness

- internal (non-structural) liner thickness. More...

External protective layer thickness

- external (non-structural) coating thickness. More...

Angle of end thickness

Angle subtended by laminate overlap length, b.

Design Factor, Df

Design factor per ASME NM.1 table 2-3.2.2-2.

Design Factor, DFt

Test mode design factor. Default: DFt=1.

Type

Laminate type specification.

Refresh SIF and k using FEA

See Integration with Nozzle-FEM

SIF

See Integration with Nozzle-FEM

Toolbar Access

Select target node and use: Insert > Insert Bend > Forged Elbow

To view element properties: