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Estimate Piping Man Hours

Calculate Man-hours in Piping Rough estimate of order of magnitude (ROM) in piping. Estimate piping man hours. In this and the subsequent post we will estimate the number of man hours needed to assemble a piping system like the one shown in the figure using three calculation methods.

  • Rough estimation of the order of magnitude (ROM).
  • Precise estimation to arrive at the most probable execution time.
  • Precise estimation with prefabricated execution.

Later we will make a comparison with the results.

Estimate Piping Man Hours – Conditions 

First, we must determine the conditions under which these estimates are valid.

  • Performance applies to carbon steel tubing and is designed in accordance with ASME B31.3.
  • The quality control of the work is performed by means of hydraulic tests (when quality control is performed NDT tests, more care must be taken in chamfering, quality control and welding).
  • The times do not include manipulation, painting, isolation, supports, scaffolding.
  • The performance of operators is not stimulated by payments per production or per task completed.
  • Work is done in standard conditions.

The criteria that define the standard conditions in which these performances apply are:

  • The site of the Works is isolated, and the execution of the Works is independent of any other plant in operation or any nearby activity affecting it.
  • The consumption of man-hours per activity is that used by a typical work team composed of a helper, a Pipefitter and a welder.
  • The work is carried out in a moderate climate (i.e., average temperatures between 5°C and 40°C) and with winds of less than 30 km/hour.
  • The area where the work is carried out is free of contamination.
  • Work is performed in daylight.
  • The work is carried out on a site with flat and dry ground.
  • The maximum height of the working plane does not exceed 1.80 m above ground level.
  • Minimum clearance height in covered areas = 2.60 m.
  • Maximum transport distance from the storage or unloading area to the work site = 300 m.
  • Operators’ entrance door is 200 m or less from the working area.
  • We receive engineering goods and supplies in a timely manner based on the project schedule.
  • Trained field personnel are available.
  • Adequate construction equipment and tools are available.
  • The project site must be at an elevation above sea level such that the altitude of the site does not require additional effort on the part of the workers.
  • Does not include man-hours consumed for fabrication of accessories.
  • The time consumed for work to correct design errors is not included.
  • The pipe is NPS 4″ SCH40.

Piping diagram

The picture shows a piping diagram where calculations are performed. Calculate man-hours

A rough estimate of the order of magnitude (ROM) in piping works and plumbing

To reach this estimate, we used the historical average value for piping assembly, which is 0.70 man-hours per inch of field weld or its inverse of 1.43 inches per hour..

The person-hours required to perform the work indicated in the table below.

A table showing the number of hours of use

The image shows the person-hours required to perform the work.
Calculate man-hours

In future articles, we will examine the precise estimate to arrive at the most likely time of execution and the precise estimate with prefabricated execution.

Estimate Piping Man Hours – Calculate Man hours