Pipes made from carbon steel lose strength at high temperatures. Electric-resistance-welded pipe is not considered satisfactory for service above 750 F, whereas furnace-buttwelded pipes are not good above 650 F. For higher temperatures, pipe made from stainless steels or other alloys should be considered.
Pressure ratings for steel pipe at different temperatures are calculated according to the ANSI B31.3 Code for Pressure Piping. ANSI B31.3 gives stress temperature values for the various steels from which pipe is fabricated"
I am not sure what you are asking. What, specifically do you mean by "explanation of" ? ... Can you reword or restate your question in better English ?
I can only guess at your question .... are you asking about the ASME B31.1 and B31.3 temperature usage restrictions for various types of EFW piping ?
Are you asking about the differences between EFW and seamless piping usage and manufacture ?
...OR what ???
Get someone else to help you in stating your question ...
EFW pipe is electric fusion welded pipe. As such the pipe base material is melted and fused together if no filler metal is used and both the base metal and weld filler metal are melted and fused as opposed to ERW (electric resistance welded) pipe.
1-The Project MTO description,is included different,EFW.ERW and SAW Pipes items.
2-If EFW is subsidery of SAW ,Why has a different pipe description in MTO.
3-According to B31.3 .There is EFW with & Without filler metal definition.
4-As I understant ,EFW without filler metal is ERW(Please confirm!)
5-As in MTO has not mentioned about EFW(With or Without filler metal),May we supply ERW or not?
Almost, SAW is a version of EFW. It could also be GTAW, GMAW, Plasma, Laser, or a few others as long as you actually melt the metal.
SAW can be done poorly (as any method can) and some people don't like it so they place limitations on it. It can be prone to higher inclusion content.
ERW does not actually melt the metal, you get it hot and plastic and squeeze it together.
EFW without filler is Autogenous welding, or you can add filler
SAW is by definition with filler.
In their EFW section do they mention filler?
As per A139/A139M scope :
1.1 This specification covers five grades of electric-fusion(arc)-welded [highlight #CC0000][/highlight]straight-seam or helical-seam steel pipe.
