Field-fit Welds and Loose Flanges

Because field-fit welds and loose flanges require fabrication on site, they will be highlighted by a message linked to the pipe end.

Messages for on-site fabricated connections

If a cut pipe list has been specified using the CUTPIPELIST command, Isodraft automatically includes a site fitting allowance in each calculated cut pipe length which is associated with:

• A flange with its LOOSE attribute set to TRUE (that means, a loose flange);

• An element of generic type WELD which has the symbol key WF (that means, a field-fit weld).

This allows for material loss during on-site preparation of the pipe end. The allowance is taken from the value of the ALLO attribute for the weld or flange, if set. If the value of ALLO is not set (or zero), the allowance defaults to 150mm. However, this default allowance can be altered by using the LOOSEFLANGEALLOWANCE command. The fabricator and/or erector can be informed of the in-built allowance by means of a message in the title block area.

For a field-fit weld in Tube, the allowance will be added to the Tube before the Weld. In order to put the allowance on the following Tube, the Weld must be flipped in Model so that p-arrive is P2.

Field fit allowance in Tube

Note: The dimension shown on the isometric drawing is the actual designed dimension.