The Pipe cutting plan shall be prepared for individual AFC piping isometric drawings by the
piping engineer. Wherever field-welded joints are shown in the piping isometric drawings,
a minimum of 200 mm extra length needs to be considered while making the cutting plan.
Cutting and beveling of pipes may be done by flame cutting, plasma cutting and machining
by using C.N.C. machine. The following shall be considered during cutting and beveling:
a) Carbon steel
Heat numbers shall be transferred by hard stamping or tagging or by any suitable method
prior to blasting and primer application. CS pipe shall be blasted and primed prior to
cutting. The cutting and beveling of CS will be done by the flame (oxyacetylene) torch
or by C.N.C. machine, and the oxides shall be removed from the surfaces by grinding to
bright metal and paint. Grease and rust shall be removed nearer to the bevel ends, if
there is any.
b) Low-alloy steel
The cutting and beveling of low-alloy steel shall be done by the flame (oxy/acetylene)
torch, and after the flame cutting, a minimum of 2 mm of material shall be removed
from the cut surface by grinding.
c) Stainless steel
The cutting and beveling of stainless steel shall be done by mechanical means using the
cutting discs or by plasma cutting (for big size and thick wall) or by C.N.C. machine, and
then the surface shall be ground to the bright metal. All the grinding discs to be used for
the stainless steel shall be iron free.
d) Galvanized materials
Galvanized material shall be cut using cold cutting methods.