# What is Inch Meter & Inch Dia in Piping System ?

In construction projects, both Inch Dia & Inch Metre are generally considered as units for measurement of quantum of piping job (mainly for welding/ Erection of piping/ hydrotest measurements). Former being denoted by ID of (phi)” or ” and inch metre by IM respectively; can be understood as below:

What is Inch Dia ?
In construction projects Inch Dia unit of Measure is used to measure the progress of Piping Spool fabrication. The weld joint of the pipe size is converted to the equivalent inch dia of welding. Examples:
1. One welding joint of 8 inch diameter pipe = 8 Inch Dia
2. Two welding joints of 12 inch diameter pipe = 24 Inch Dia

What is Inch Meter?
In construction projects Inch Meter unit of Measure is used to measure the progress of Piping Erection and Hydrotesting. The length of pipe erected or hydrotested of the pipe size is converted to the equivalent inch Meter of erection or hydrotesting.
Examples:
1. 10 Meter of 8 inch diameter pipe Erected or Hydrotested = 80 Inch Meter
2. 12 Meter of 6 inch diameter pipe Erected or Hydrotested = 72 Inch Meter.

Let see clear example that how to calculate Inch Dia and Inch Meter.

Consider a 8″ NB pipe of length says 20 metres. If there are 3 joints of this pipe to be welded, the quantum of this welding job is calculated as:

DI = *Pipe Dia (in inches ~ 8) x No. of joints (~3) = 24  Dia-Inch

*Notes: The joint included of Flanges, Branchs, Fittings (the Pipe Dia in Formular will be changed as per actual Dia on each item respectively)

In terms of IM, we say the quantum of the job as:

IM = Pipe Dia (in inches~8) x No. of Metres (~20) = 160  Inch-metre

Once again, DI is generally taken as a unit of measurement (of quantum of the job) for Welding, Radiography (RT), DPI, MT, PAUT tests and are used as units for payment purposes with NDT agency.