This document provides an introduction to piping and pipelines. It discusses different types of pipes including seamless, welded, butt-welded, and spiral-welded pipes. It also covers piping terminology like nominal bore, nominal pipe size, schedule number, and wall thickness. Piping is used widely in industries like oil and gas, chemicals, and pharmaceuticals to transport fluids and gases over both long distances as pipelines and within plant boundaries. Piping must be designed, fabricated, and installed according to codes and standards.

1. INTRODUCTION TO PIPING
AND PIPE LINES

2. PIPES
• It is a Tubular item made of metal, plastic, glass etc.
meant for conveying Liquid, Gas or any thing that flows.
• It is a very important component for any industrial plant.
And it’s engineering plays a major part in overall
engineering of a Plant.
• Two types of pipes are : Seamed or Welded Pipes and
Seamless Pipe.
• Seamless pipes are wrought tubular product made
without a welded seam by drawing or extrusion process.
• Welded pipes are manufactured by EFW (Electric fusion
welding) or ERW (electric resistance welding) Process.
The longitudinal seam is welded by manual or automatic
electric arc process.

3. SEAMLESS PIPES
• Seamless pipe is formed by piercing a solid, near-molten,
steel rod, called a billet, with a mandrel to produce a
pipe that has no seams or joints.

4. BUTT WELDED PIPE
• Butt-welded pipe is formed by feeding hot steel plate
through shapers that will roll it into a hollow circular
shape. Forcibly squeezing the two ends of the plate will
together produce fused joint or seam.

5. SPIRAL WELDED PIPE
• Spiral-welded pipe is formed by twisting strips of metal
into a spiral shape, then welding where the edges join
one another to form a seam. This type of pipe is
restricted to piping system using low pressure due to its
thin wall.

7.  NOMINAL BORE
The nominal bore of a pipe is its internal diameter. The
nominal bore determines how much volume you have in
the pipe to transport your particular substance.
 NOMINAL PIPE SIZE (NPS)
NPS is a North American set of standard sizes for pipes
used for high or low pressure and temperature. Pipe size
is specified with two non-dimensional numbers: NPS for
diameter based on inches and a schedule for wall
thickness.
• For NPS 1/8 to 12, NPS is equal to Inside diameter in
inches and for NPS 14 & above NPS is equal to outside
diameter.

8. SCHEDULE NUMBER
• Pipes are designated by schedule number.
• Schedule number is represented by the pressure carrying
capacity of the pipe.
1000 x P (Internal pressure)
• Sch .No =
S(Allowable tensile strength of material)
• Irrespective of pipe diameter, equal schedules have equal
pressure carrying capacity.
• For stainless steels schedule number are designated by
suffix S i.e. 5S, 10S, 40S, 80S etc.
• XS means extra strong, XXS means double extra strong.

9. PIPE WALL THICKNESS
• Calculation of pipe wall thickness is based on thin
cylinder formula which states that required thickness “t”
for internal pressure “P” and outside diameter “D” is
given by: (for seamless pipes)
t = PD
2S
Where S = safe stress value in Kg/cm2
D & t in cm
P in Kg/cm2

10. • If we consider welded pipes with weld efficiency value “E”,
then
t = PD
2SE
E is generally expressed in decimal fraction or percentage,
E = 0.8 or 80%
• Pipes are always given tolerance on thickness. Standard
thickness tolerance for manufacturing ( also called as mill
tolerance ) is + or – 12.5% of minimum required thickness.
Also for corrosive medium, pipes are given certain
corrosion allowance “C” expressed in mm.
• Additionally sometimes extra allowance (a) is required to
take care of thickness reduction due to threading or
grooving.

11. • Thus,
0.875 X T = t + C + a
T is actual nominal thickness

12. CLASSIFICATION BASED ON END USE
 LINE PIPE
It is mainly used for conveying fluids over long distances
and are subjected to fluid pressure. It is usually not
subjected to high temperature
 PRESSURE PIPE
These are subjected to fluid pressure and temperature.
Fluid pressure in generally internal pressure or may be
external pressure (eg. jacketed piping ) and are mainly used
as plant piping.
 STRUCTURAL PIPE
These are not used for conveying fluids and not subjected
to fluid pressures or temperature. They are used as
structural components (eg. handrails, columns, sleeves etc.)
and are subjected to static loads only.

13. DIFFERENCE BETWEEN PIPE AND
TUBE
• Pipe is identified by Nominal bore and thickness is
defined by schedule.
• Tube is identified by Outside diameter and thickness
is defined by Birmingham's wire gauge.

14. PIPING
• Piping is defined as large series and networks of pipe
within the well defined boundaries of the plant/plot
with all fittings and equipments like pump, valves
and other miscellaneous items with an intention to
transfer fluid from one facility to another with in
those boundaries as required.
• “Piping systems are like arteries and veins. They carry
the lifeblood of modern civilization.”

15.  Two types of piping are:
• UNDERGROUND PIPING
Underground piping are routed underground or buried
underground. U/G, Buried piping should be properly
protected from corrosion. Pipe may be properly wrapped
and coated to prevent corrosion Or U/G piping be
protected by using Cathodic protection. Mainly coal tar
tapes are used for wrapping.
• ABOVEGROUND PIPING
Aboveground piping are pipelines above the ground
level. Pipes are protected from corrosion by painting.
Before painting pipes should be properly blasted to make
surface rough.

17. PIPELINES
• Pipelines are defined as long series of pipes usually of
large diameter often underground with few fittings and
equipments mostly pumps and valves (mainly to control
the flow, that are laid with an intention to transport any
fluid (liquid or gas) over long distances.
• Pipeline engineering deals with transport of
hydrocarbons with huge capacity through long distances.

19. PIPING APPLICATIONS
• OIL AND GAS SECTOR
• CHEMICAL PLANTS
• PAPER AND TEXTILE
• PHARMACEUTICALS
• FOOD AND BEVERAGE
• COMMERCIAL PURPOSE

20. EXPECTATIONS FROM PIPING
ENGINEER
• Wide engineering knowledge
• Awareness of standards, codes and practices
• Methods of pipe fabrications and erection
• Knowledge about equipments used
• Knowledge about design and layouts

21. BLOCK DIAGRAM OF PIPING ENGINEERING
PROCESS FLOW
DIAGRAM
EQUIPMENT
LAYOUT
PIPING GENERAL
ARRANGEMENT MATERIAL TAKE OFF
PURCHASE SPECIFICATION
PIPE SUPPORT
GAD
PIPE SUPPORT
INSTALLATION
ISOMETRIC DRAWINGS
FABRICATION
DRAWINGS
FABRICATION
DRAWINGS
PIPING &
INSTRUMENTATION
DIAGRAM

23. LIFE CYCLE OF PROCESS PLANT
• TECHNO ECONOMIC FEASIBILITY
• DESIGN PHASE
• CONSTRUCTION PHASE
• COMMISSIONING PHASE
• OPERATION/PRODUCTION PHASE

24. INSULATION
• INSULATION - Insulations are done to prevent heat
transfer. When hot fluid flows through pipe then
generally pipe is insulated.
• There are two primary reasons for insulating the pipe
carrying hot fluid.
Containing the heat inside the pipe. Insulation preserves
the heat of the fluid. It is called Hot Insulation.
Personnel safety, so that people do not get burn injury by
touching hot surface of pipe. It is called Personnel
Protection Insulation.

25. • Cold pipes are also insulated.
Cold or chilled fluid carrying pipes are insulated to
prevent heating of cold fluid from outside. It is called Cold
Insulation.
Some times cold pipes are insulated to prevent
condensation of atmospheric water vapour on pipe
surface. It is called Anti-Sweat Insulation.
• Other types of Insulation
When gas flows through pipes at high velocity, it creates
noise. In such cases pipes are insulated to reduce noise. It
is called Acoustic Insulation.
Some times pipe and it’s content are heated from
outside, by heat tracing element. In that case pipe along
with heat tracing element are insulated to conserve the
heat of the tracer. It is called Heat Tracing Insulation.

26. • INSULATION MATERIAL - The insulating material should
be bad conductor of heat.
• There are two basic categories
• 1) Fibrous Material, which has large voids full of air
between fibers - Cork, Glass Wool, Mineral Wool, Organic
Fibers. Note stagnant air is a bad conductor.
• 2) Cellular Material, which has closed void cells full of air -
Calcium Silicate, Cellular Glass (Foam Glass),
Polyurethane Foam (PUF), Polystyrene (Thermocol), etc.
Some times Cast material like Cement Plaster or Plaster
of Paris are also used.
• INSULATION CLADDING - Insulation materials are
generally soft or fragile. So the outer surface of insulation
are protected with Aluminum sheet or GI sheet cladding.

28. TYPES OF FLOW
 STEADY OR UNSTEADY FLOW
• In steady fluid flow, the velocity of the fluid is constant at
any point.
• When the flow is unsteady, the fluid’s velocity can differ
between any two points.
• Steady-state flow refers to the condition where the fluid
properties at a point in the system do not change over
time. Otherwise, flow is called unsteady.

29.  VISCOUS OR NON-VISCOUS FLOW
• Viscosity is actually a measure of friction in the fluid.
When a fluid flows, the layers of fluid rub against one
another, and in very viscous fluids, the friction is so great
that the layers of flow pull against one other and hamper
that flow.
• Viscosity usually varies with temperature, because when
the molecules of a fluid are moving faster (when the fluid
is warmer), the molecules can more easily slide over each
other.

30.  COMPRESSIBLE OR INCOMPRESSIBLE FLOW
• Fluid flow can be compressible or incompressible,
depending on whether you can easily compress the fluid.
Liquids are usually nearly impossible to compress,
whereas gases are very compressible.
• All fluids are compressible to some extent, that is,
changes in pressure or temperature will result in changes
in density. However, in many situations the changes in
pressure and temperature are sufficiently small that the
changes in density are negligible. In this case the flow can
be modelled as an incompressible flow.

31.  LAMINAR AND TURBULENT FLOWS
• Laminar flow is fluid motion in which all the particles in
the fluid are moving in a straight line. Where the fluid
moves slowly in layers in a pipe, without much mixing
among the layers. Typically occurs when the velocity is
low or the fluid is very viscous.
• Turbulent flow is an irregular flow of particles;
characterized by whirlpool-like regions. Opposite of
laminar, where considerable mixing occurs, velocities are
high.
• Laminar and Turbulent flows can be characterized by
using Reynolds Number. NR < 2000 – laminar flow ,NR >
4000 – Turbulent flow.
• For 2000 < NR < 4000 – transition region or critical region
- flow can either be laminar of turbulent

32. NR = V D ρ = V D
ή ν
Where NR – Reynolds number
V – velocity of flow (m/s)
D – diameter of pipe (m)
ρ – density of water (kg/m3)
ή – dynamic viscosity (kg/m . s)
ν – kinematic viscosity (m2/s)