Weld symbol diameter

 

It's the Sphere diameter.
It's used for "centerline" representaton of the piping (3D model and 2d drawing)

Thank you Corrado but i wonder how i can calculate or estimate the diameter of the sphere?

Generally the Sphere diameter is kept same as the Pipe Diameter in NB.
You can refer the Catalogue /00WB200 in the Master project for reference.

The following weld types have symbols associated with them. They can therefore be shown on isometrics:
WS Site (erection) weld
WF Field-fitted weld
WW Shop (fabrication) weld

By default, all types of weld are shown on isometrics. You can use the WELDTYPE command to specify that:
•  Only shop welds will be shown;
•  Only site welds will be shown;
•  No welds will be shown;
•  All welded fittings will be shown as having shop welds.

$* How's Life in Syria Now ?

Thank you very much azmatbaig. Life in Syria is getting better but we have many challenges regarding rehabilitation of oil and gas facilities that were destroyed partially during the war.