Diameter inch calculation

Inch Diameter Calculation 

How are inches of weld in piping counted?

The number of diametral inches welded depends on the design and specifications of the piping system.
For example, a piping project typically involves the installation of pipe runs and fittings of different diameters, with each welded joint contributing to the count. It is necessary to consult the piping drawings, specifications, or project documentation to determine the exact number.
Here is a typical case of how to count inches of weld using the picture in the book  "Estimator's Piping Man-hours Tool"

 Number of Inches of Weld

Diameter Inch Calculation. The illustration above shows a discharge line starting at the discharge flange (2 1/2" diameter) of a centrifugal pump and then connecting by a 2 1/2" x 4" concentric reducer to a 4" diameter line terminating in an NPS 6" manifold.

To count the number of inches, count the welds according to the following table.

We notice that for the number of welds we only consider the diameters of the components of the section we are considering. In the next entry, we will analyze how the thickness (SCH), the pipe materials and the external conditions affect the welding times for the same pipe diameter.