Piping notes

DISADVANTAGES OF FIELD FABRICATION

• Weather is arguably the biggest deterrent. If the facility under construction is not enclosed then protection from the elements will have to be provided.
• When welding has to be done in conditions that are not environmentally controlled then pre-heating will be required if the ambient temperature (not the metal surface temperature) is 0° F or below.
• In a new facility, as opposed to having to route piping through an array of poorly located existing pipe and equipment, field fabrication of buttwelded pipe is not as efficient and cost effective as shop fabrication.
• Concerns about safety and efficiency when working in a facility while it is in operation in advance of a turnaround or to begin advance work on a plant expansion.

Generally speaking, threaded, socketweld, grooved, and other proprietary type joints that do not require buttwelding are field fabricated and installed. Buttwelding of small (bore), NPS 1½ and less, are very often field fabricated and installed because of the added risk of damage during transport, in pre-fabricated form, from the shop to the site.

Pipe rolling machine in Field Fabrication