Dear All

I have to connect two steam pipeline. Smaller pipe (new pipe) is of size 3" (branch pipe) whereas larger pipe (existing) of 8" size (main steam pipe).

Material for both pipe is SA 335 P91

Design pressure - 145 kg/cm2

Design Temp - 545 deg C

Fluid - High pressure steam

Kindly advice me in brief how to make connection between these two pipes.

Also please explain whether the SPOOL piece used for this purpose or not along with concept of SPOOL piece.

Thanks in advance.

Another worrying post.

If you have to ask such basic questions, should you be dealing with high pressure and high temperature steam in the first place ? Instant death awaits the unwary (and unqualified).

Anyway ... joining pipe .... It rather depends upon whether the pipes are co-axial or perpendicular. I would recommend a reducer (maybe two reducers) for the former or a reducing tee or weldolet for the latter.

A spool piece is a piece of pipe, commonly flanged.