Pipe system components
Types of pipes
Pipe joints methods
Pipe materials
A Piping System is an assembly of various components put together with a proper method of joints, functionally to transport fluid from its source to destination. The different components put together are defined as piping components.
They are designed for withstanding the operating and design conditions specified in the process parameters. Each component used in piping systems are specified in piping specification.
Pipe system components used are
1. Pipe
2. Pipe fittings
3. Flanges
4. Gaskets
5. Bolting
6. Valves
7. Specialities
Pipe:
Pipe is a tubular product used to convey a fluid. The pipe sizes are generally identified as nominal bore (NB) or nominal pipe size (NPS). Pipes have fixed outside diameter (O/D) and variable inside diameter based on the thickness selected.
The codes used for pipe selection are
ASME B 36.10- Welded and seamless wrought steel pipes
ASME B 36.9- Stainless steel pipes
The different sizes and thickness which are available are specified in above standards.
Thickness of pipe is generally designated by schedule no. and the corresponding thickness specified.
Types of pipes:
1. Seamless:
Pipe produced by piercing a billet followed by rolling or drawing or both.
They are used for high pressure applications.
2. Welded:
a. Electric fusion welded (EFW): Pipes carrying a single or double longitudinal but weld joined wherein coalescence is produced by manual or automatic electric arc welding in the preformed tube.
b. Electric resistance welded: (ERW): Pipe carrying ongitudinal but weld joined wherein coalescence is produced by heat obtained from resistance of the pipe to flow of electric current in a circuit of which the pipe is a part and by application of pressure.
3. Forged and bored:
Pipes prepared by forging and then boring to the desired thickness.
Various methods of pipe joints:
1. Butt weld pipe joints
2. Socket weld pipe joints
3. Screwed pipe joints
4. Flanged pipe joints
5. Spigot socket pipe joints
Generally used pipe materials are
Carbon steel:
ASTM A53- welded and seamless pipe, black and galvanised.
ASTM A106- Seamless cs pipe for high temperature services.
ASTM A672- Electric fusion welded steel pipe for high pressure service at moderate temperature services.
Stainless steel:
ASTM A312- Seamless and welded steel pipe for low temperature services.
A409-welded large diameter austenitic steel pipe for corrosive and high temperature services.
ASTM A358- Electric fusion welded austenitic chrome -nickel steel pipe for high temperature services.
Low alloy steel:
ASTM A335- Seamless ferritic alloy steel pipe for high temperature services.
ASTM A691- Carbon and alloy steel pipe, electric fusion welded for high pressure service at high temperature.
Low temperature carbon steel:
ASTM A333- Seamless and welded steel pipe for low temperature services.
ASTM A671- Electric fusion welded steel pipe for atmpospheric and low temperature services(sizes >=16in NB)