Introduction to Piping Design

Introduction to Piping
Design

Snehal Dhamale
Snehal Nalawade.
Piping Design Engineer
Offshore oil and gas industry
Onshore oil and gas industry
Piping System

• The piping system is group of pipes , fittings

and flanges which connects equipment and
pipelines inside stations
Piping System

• Piping systems includes :

1. The pipes , fittings and flanges .
2. Valves.
3. Gaskets and bolts
4. Special Piping Components ( Insulation
Gaskets, Special Valves, Filters and
strainers, Corrosion Protection Fittings,
etc).
5. Pipe Supports
International Standards of Design
• ASME B31.3 : Process Piping
• ASME B31.1 : Power Piping
• ASME B31.5 :Refrigeration piping and heat
transfer components.
• ASME B31.8 :Gas transmission and
distribution piping systems.
• ASME B31.9: Building services piping
Piping System Configuration

Welded Configuration.
A. Socket Welded.

B. Butt Welded.
Piping System Configuration
C. Threaded Configuration .
 Piping Components
Pipes
• The main component of the piping system.
• Sizes can be prescribed in :
A. NPS (Nominal Pipe Size –Inch System ).
B. DN ( Diameter Nominal – mm System)
• For the NPS system , 2 dimensional standards can be
used :
A. ASME B36.10 (CS dimensions)
B. ASME B36.19 (SS dimensions)
• For NPS thickness described in Schedule (Schedule 10,
20, 30,40 , STD,
XS,XXS ,etc).
Pipes
Elbows
• Used for any change in direction .
• Long Radius ( 1.5D) or Short Radius.
• Dimensional Standards (ASME B16.9).
• Sizes and thickness designation same as
pipe.
Elbows
Flanges
• Used in the places in which the pipe shall be easily
dismantled for Maintenance.
• Used to attach piping system to equipment's.
• Source of leakage in the piping system.
• Pressure rating is defined by the Manufacturing Standard
(Not by pipe thickness).
• ASME Pressure Rating :150#,300#,400#,600#,900#,1500#
and
2500#.
• API Pressure Rating : 2000#, 3000#, 5000#, 10000#,
15000#,
20000#
• Dimensional and Pressure Rating Standard is ASME
B16.5 ASME B16.47,API 6A).
Flanges
Caps

Reducers
Tees and Crosses
Gaskets
• Spiral
Wound
• Flat Ring
• Ring
Gasket
Spiral Wound
• The most common used gasket component.
• Can seal under heavy operating conditions .
• Manufactured as per ASME B16.20
• Easy installation due the robust shape of the
gasket..
• Filler ring can be graphite, PTFE , Magnesium
mica, Flexible graphite, Ceramic.
• Major component : Spiral Wound with the filler
material (Sealing Element), Inner ring and
Outer(Centering) ring.
Spiral Wound
Flat Ring
Gasket
• Used usually for lower pressure rating
150#- 300# and lower temperature.
• Less torqueing value in compare with
the same rating of SW gaskets.
• Manufactured from elastomer material.
• Less cost.
Flat Ring
Gasket
Stud Bolts
• Bolts are used to connect the flange
joints.
• Bolt length shall be calculated to satisfy
the client requirements such as exposed
threads.
Valves
• Gate Valves
• Ball Valves
• Globe Valves
• Butterfly valves
• Check Valves
• Choke Valves
• Plug Valves
• Safety Relief Valves
Stages of piping Design from Start to the project End

• Manual Draughting
SOW Study and

Project SOW Study Site Design

Start and Data Survey Basis
collection Memorandu
m

Equipment Piping Material

Layouts/Nozz Plot Class Piping
le Plants Specifications Specifications
Orientation

Key Piping Stress Piping

Plans GA’s Analysis Isometrics

Support Piping Bulk Supports

Schedule MTO Details
2D Piping Layout
Stages of piping Design from Start to the project End

• 3d Modeling
Project Start

SOW Study Design Basis

and Data Site
collection Survey
Memorandum

3D Model Piping
Plot Piping
Specification Material
Plants Specificatio
Class
ns
Specifications

Supports
Equipment's Piping Model
Modeling Modeling Modeling Review
by client

Piping Piping Piping Key

Bulk Isometrics GA’s Plans
MTO
Plant Piping 3D Modelling
Design Basis
• This document includes the following :
A. The scope of the design .
B. The Design approach (Which documents
will be submitted , the international codes
and standards to be used, client standards
to be used , the material selection
criteria, the design assumptions ,etc).
• This documents defines how the design
shall be done, and shall be submitted and
approved in the beginning of the project to
avoid rework.
Plot Plans
• Scale between 1:200 up to 1:2000.
• Defines the scope of the project .
• The main purpose of this drawing is the area allocation and
the
overall plant design.
• Area allocation includes required areas and coordinates.
• Plot plans show the location of all the buildings, equipment,
pipe racks, and other items of importance in the unit.
• True north and plant north are also shown.
• Includes the Road/Access outlines
• Shows sometimes the coordinates of the major equipment.
• Sometimes the plant Coordinate System is defined on
the plot plan
Piping Plot Plans
Equipment Layout
• Developed after the plot plant .
• Shows the equipment's arrangement ,
locations, spacing and maintenance
spacing.
Equipment Layout
Piping General Arrangement /Layout
• The most important Drawing in for the
piping engineer.
• Developed from the plot plan and Equipment
layout, or directly from the 3D Model.
• Shows the pipes routing and supports
locations, access platforms, etc .
• Shows also all the valves operation requirements.
• Fully developed piping GA shall
provide full information for piping
Fabrications.
• The piping GA used for piping erection.
Piping General Arrangement
Piping Isometrics
• An isometric is a type of three-dimensional
drawing known as a pictorial.
• Isometrics, or Iso's as they are commonly
called, are developed using the three primary
dimensions of an object: height, width, and
depth.
• the isometric combines the three dimensions of
the object into a single view to provide a
pictorial representation.
• Includes all the material Call Out and the Material
Take Off.
• Used for Fabrication Purposes, and some
times for Erection.
Piping Isometrics
Piping Bulk MTO
• List Type Document .
• Includes all the piping material (Non consumables)
which shall be installed in the project.
• Includes Items Description, Quantity and
special requirement for the items to be
procured.
• Input to the procurement
• Done in stages:
A. 70% (In the beginning of the project)
B. 80% (After issuing 50% of the Iso’s)
C. 90% (After issuing 100% of the Iso’s)
D. 100%. (After issuing all the ISO’s for Construction)
Other Drawings and
documents

• Stress Analysis Reports

• Piping Key Plans.
• Nozzle orientations
Piping Stress Analysis
• The process of calculation stresses on pipe , to ensure
piping flexibility, structural integrity and to ensure system
operability.
• The main purpose of stress analysis is to ensure
that piping system has sufficient flexibility / rigidity to
prevent any of the followings,:
A. Failure of piping from overstress or fatigue.
B. Leakage at joints (Especially the Flanged Joints).
C. Detrimental stress or distortion in piping or connected
mechanical equipment such as Pig launcher/receiver, KO
Drum and gas filters and metering skid, pumps, etc.
resulting from excessive thrust and moments in piping.
D. Undesired displacement of the pipes.
E. Excessive loads and moments on connected equipment,
anchor points, flanged connections, etc.
CAESAR II Input
screen
Piping Testing Requirements
• Piping Design Engineer Decides the testing
requirements of piping system based on the
codes and standards.
• Testing requirements includes but not limited to :
A. Visual testing .
B. Non Destructive Test : Extents and
percentage of radiography of welds, Extent
and percentage of MPI/LPT of welds.
C. Leak test of the piping system : Service Test/
Hydrostatic test /Pneumatic Test /Sensitive leak
test.
Hydrostat Pressure/Leak test
• Used to check the system integrity ,and the
leakage which may occur on the joints.
• Water is used as testing medium , some times
other medium are used .
• As per ASME B31.3 , systems shall be
pressurized to
1.5 Design pressure.
• For the piping system dealing with gasses ,
additional temporary supports may need to be
considered.
• Holding Time depends on the time the
inspector needs to check all the joints
(Minimum 10 Minutes for ASME B31.3 and
Pneumatic Pressure/Leak test
• Used to check the system integrity ,and
the leakage which may occur on the
joints.
• Air , Nitrogen , Argon , Helium are
used as testing media.
• Usually used for small bore piping
system.
• More safety consideration shall be
taken for such test .
Thank You.