A question on thick walled pipe

[arunmrao]

A recent question in Mechanical Engineering forum left me wondering on the subject of thick walled pipes.

How are these pipes (2" wall thicknes) possibly manufactured ? Perhaps it is very commonly used in oil industry,I shall be thankful if any member can share his experience.

Chocolates,men,coffee: are somethings liked better rich!!
(noticed in a coffee shop)

 

[SJones]

ASTM A369

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[CoryPad]

Arun,

See this document from Sumitomo:

http://www.sumitomometals.co.jp/e/business/sm-series.pdf

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[metengr]

Arun;
My expierence with piping that is 2" wall or thicker is that it can be manufactured either seamless (from a forged and bored billet) or seam welded (rolled and welded plate). ASTM/ASME or API material specifications are commonly used for procurement of pipe.

One of the most important decisions regarding heavy wall pipe is to decide on seamless or seam welded options. This requires careful consideration of service application for the pipe - material, temperature and application (environment).

 

[redpicker]

The method of manufacture really depends on the service requirements. With heavy wall tubulars, the stresses are usually low, but, in general, if the service stresses require high strength steels, seamless if preferred because of weldability issues and strength concerns (both yeild and toughness) of the weld.

While some mills may have the ability to pierce walls in the 2" range, that is really pushing it. Nearly all of the heavy wall seamless tubulars used in the oil-field are bored from solid bar, usually after heat treatment. The boring operation itself is somewhat unique. Known as trepanning, the hole is cored (you make less chips, therefore less work) and, unlike normal drilling, where the workpiece is held steady and the cutting tool turned, with these processes, the bar is rotated and the cutting tool is held stationairy. This helps the hole stay in the center. In addition, it is not uncommon for the drilling to be performed at each end and (hopefully) meet up in the center. Normal lengths are around 30 feet, but up to 60 feet (or more) are processed this way.

rp

 

[limey1]

Ive seen alot of stainless, seamless piping with a wall thickness up to 2.75". This was almost exclusively hot extruded as its very easy to produce.(Low Press force requirement). Common length ive seen in these sizes is typically @ 24'- 30'.