Small pipe size welding spec, STD and requirement

[siriwatl]

HI,
Anyone can help me answer the question below?
1) In general pieces of pipe shall be connected to each other to form the required line as follows:
- 1 ½" and smaller, socket weld via fitting. (Can it be lower to 3/4" & why?).
- 2" and larger, butt weld, pipe-to-pipe. (Can it be lower to 1" & why?)

2) In general socket weld flanges shall be used up to and including NPS 1 ½" (Can it be lower to 3/4" & why?) and Welding-neck flanges for NPS 2" and larger (Can it be lower to 1" & why?).

Thanks for the answer inadvance.

[ThaMaestro]

What

[siriwatl]

For item 1) to weld the pipe to pipe by using socket weld type, what is the minimum size that we should consider as per the question in the thread above.
For item 2) it's about the welding-neck flange

Since I want to know the minimum size that we can go in the industrial practice or standard required.

[Inspector.Soldadura]

HI,
Anyone can help me answer the question below?
1) In general pieces of pipe shall be connected to each other to form the required line as follows:
- 1 ½" and smaller, socket weld via fitting. (Can it be lower to 3/4" & why?).
- 2" and larger, butt weld, pipe-to-pipe. (Can it be lower to 1" & why?)

2) In general socket weld flanges shall be used up to and including NPS 1 ½" (Can it be lower to 3/4" & why?) and Welding-neck flanges for NPS 2" and larger (Can it be lower to 1" & why?).

Thanks for the answer inadvance.

I think you are talking about PIPE CLASS requirements.

[siriwatl]

Actually I am talking about the minimum pipe size that shall be used butt weld as per industrial practice.
And about the minimum of weld neck flange that shall be used.