Miter Bend (Closely-spaced)

Closely-spaced miter bends must comply with ASME B31.1 code requirements.

Other ASME B31 codes:

If or model widely-spaced miter joints using single miter joints.

A welded miter joint consists of multiple miters and half-miters. The number of joints (with axis direction changes) affects intensification and flexibility factor calculations. Figure 1 shows a configuration with 3 joints. The skew angle is provided for reference.

The central bend angle must not exceed 90 degrees (More...).

Fig. 1

START-PROF performs wall thickness checks for miter bends according to the selected design code.

Properties

 

Property

Description

Name

Element identifier. When checked, displays in 3D view.

Qualified Bend

When checked, uses mpsb=1.0; otherwise uses mpsb=1.3.

Radius, R

Average bend radius (0.5D)

Get properties from matching pipe

Retrieves properties from adjacent pipe elements.

Calculate weight automatically

When selected, calculates weight as frustum volume using wall thickness from adjoining pipes.

Weight

Bend weight including flanges (excluding insulation and product content). Set according to standards without overload factors. Product and insulation weights with overload factors are automatically calculated from adjacent pipes.

Calculate angle automatically

The bend angle used in flexibility factor (k-factor) calculations for certain codes. Enable by default for automatic calculation.

Disable when the bend is split into multiple segments for support modeling. Specify the full bend angle for each segment in this case.

Angle

Material

Material selection from the materials database.

Longitudinal Weld Joint Efficiency Factor, E

Longitudinal weld joint efficiency factor. More...

Manufacturing technology

For ASME B31.1, ASME B31.3, DL/T 5366-2014: seamless pipe uses Wl=1.0; electric-welded pipe uses database values. More...

For GOST 32388-2013, material properties vary by pipe type (seamless/welded) from the materials database.

Presence of flanges

Specify flange configuration. Flanges act as rigid elements that prevent cross-section ovalization and affect flexibility and stress intensification factors.

  • none - both ends welded to pipes

  • one flange - one flanged end, one welded end

  • two flanges - both ends connected with flanges

Number of miters

Number of miter segments (see Figure 1).

Skew angle

Skew angle for each miter segment (see Figure 1).

Mill tolerance

Manufacturing tolerance at production. More...

Corrosion and wear allowance

Wall thickness allowance for corrosion and wear (working mill tolerance). More...

Nominal wall thickness, S

Nominal (actual) wall thickness.

Stress correlation along two axes, r

Based on ISO 14692 section 7.10.

Qualified stress, qs

If blank, retrieves value from material database. Based on ISO 14692 section 7.8.

Design Factor, Df

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

Design Factor, DFt

Design factor for test conditions (default: DFt=1).

Type

Laminate type specification.

Internal protective layer thickness

- internal (non-reinforced) protective layer thickness. More...

External protective layer thickness

- external (non-reinforced) protective layer thickness. More...

Toolbar Access

To insert a miter bend, select the desired node and use: Insert > Insert Bend > Miter Bend (Closely-spaced)

To view existing element properties: